Intramuscular Procaine Research Articles

Plasma Creatine Kinase and Aspartate Aminotransferase Activities Before, During, and After 5 Days of Intramuscular Penicillin Administration in Sedentary Horses.

Muscle damage can result in leakage of intracellular enzymes such as creatine kinase (CK) and aspartate transaminase (AST) into plasma. There are no controlled documentations of the effects of intramuscular antibiotic drug administration on plasma CK and AST activities in horses. The objective of this experiment was to test the hypothesis that 5 days of intramuscular procaine penicillin G injection in normal horses would result in increased plasma activities of CK and AST. Nine healthy adult horses were sampled for 7 days preceding, 5 days during, and 32 days following procaine penicillin G (22,000 IU/kg) administration intramuscularly twice daily. Heparinized jugular venous blood samples were obtained daily before treatment and were analyzed the same day for plasma activities of CK and AST. Repeated measures ANOVA and post hoc Tukey's Test were used to identify days where CK or AST were elevated compared to control means at a significance level of P < .05. Beginning the day after first injection, plasma CK increased above the reference range, peaking at 2,046 ± 627 U/L after 3 days, and returned to 227 ± 57.3 U/L (within the reference range) 9 days after treatment began. Beginning the day after first injection, plasma AST increased, peaking at 703 ± 135 U/L on the day after the last injection. Plasma AST did not return to the reference range in all individual horses until 29 days after the last injection (mean 247 ± 33 U/L). Compared to the control period, plasma CK and AST elevations lasted for 8 and 28 days, respectively, after the onset of treatment (P < .001 to P=.03) and lasted for 4 and 24 days, respectively, after the last day of treatment (P < .001 to P=.03).

Acute phase protein concentrations following serial procaine penicillin G injections in horses.

Acute phase protein (APP) measurement is used to detect inflammation. Intramuscular (IM) injections could cause tissue injury and induce an acute phase response (APR). To evaluate the effects of IM procaine penicillin G (PPG) injections on APP concentrations in horses. Prospective longitudinal design. PPG was administered intramuscularly to six horses, twice daily, for 5 days. Plasma fibrinogen (FIB), serum amyloid A (SAA), haptoglobin (HAP), creatine kinase (CK), and aspartate aminotransferase (AST) were quantified daily for 5 days before the first injection, during the course of administration, and for 4 days after the final dose. Analytes were quantified every other day for the remaining 16 days. Data were compared using a parametric or non-parametric repeated measures ANOVA and a Tukey's or Mann-Whitney rank sum test, respectively. Significance was set at p < 0.05. CK was increased over baseline (mean ± SD: 200 ± 74 IU/L) on Days 1-6 (p < 0.001 to p=0.02, mean ± SD: 723-1177 ± 355-544 IU/L) and AST was increased above baseline (mean ± SD: 233 ± 58 IU/L) on Days 2-7 and 10 (p < 0.001 to p=0.05, mean ± SD: 307-437 ± 79-146 IU/L). Increased FIB was noted over baseline (mean ± SD: 177 ± 30 mg/dl) on Days 6-8 and 10 (p=0.02 to p=0.03, mean ± SD: 234-252 ± 33-49 mg/dl). SAA was increased above baseline (mean ± SD: 4.7 ± 2.9) on Day 6 (p=0.02, mean ± SD: 113 ± 186 μg/ml). There was no change in HAP. Healthy horses were used, small sample size, and a lack of a negative control group. Serial intramuscular procaine penicillin G (IM PPG) injections may result in increased positive APP concentrations in horses and this must be considered when these test results are interpreted.

Clinical and serological outcomes in patients treated with oral doxycycline for early neurosyphilis.

Penicillin-based antibiotic treatment for syphilis infection with CNS involvement (early neurosyphilis) is not always a suitable treatment option. We compared outcomes of patients diagnosed with early neurosyphilis and treated with doxycycline or procaine G penicillin. Serological and clinical outcomes were analysed in patients diagnosed with early neurosyphilis between January 2015 and October 2019 at 56 Dean Street, a combined sexual health and HIV service based in London, UK. Acute onset of CNS, ocular and/or otic symptomatology and a documented seroconverting syphilis serology or a >4-fold increase in rapid plasma reagin ('RPR)' test titre within the previous 12 months were criteria used to define a case. Mann-Whitney U-test and χ2 tests were used to test distributions between baseline characteristics and outcomes according to treatment administered. Eighty-seven patients were included: median age = 35 years (IQR = 31-45), 98% MSM, 79% white ethnicity, 53% HIV-1 positive and 40% previously diagnosed with syphilis at any stage. They were treated exclusively with either intramuscular (IM) procaine G penicillin (71%) or oral doxycycline (18%). Patients received doxycycline treatment over a penicillin-based regimen due to IM treatment declined (31%), inability to attend for IM injections (31%) or penicillin allergy (19%). Serological response was achieved by all patients; 91% reported full symptom resolution at 30 days from end of treatment. Similar rates of clinical and serological response and seroreversion were observed in the groups treated with procaine G penicillin versus doxycycline. The clinical and serological outcomes seen with penicillin-based versus doxycycline treatments were similar. A randomized controlled trial is needed to establish the effectiveness of doxycycline in the treatment of early neurosyphilis.

"Sex in the Time of COVID": Clinical Guidelines for Sexually Transmitted Disease Management in an Era of Social Distancing.

"Sex in the Time of COVID": Clinical Guidelines for Sexually Transmitted Disease Management in an Era of Social Distancing.

Neurosyphilis Treatment Outcomes After Intravenous Penicillin G Versus Intramuscular Procaine Penicillin Plus Oral Probenecid.

Data comparing neurosyphilis treatment regimens are limited. Participants were enrolled in a study of cerebrospinal fluid (CSF) abnormalities in syphilis that was conducted at the University of Washington between April 2003 to May 2014. They were diagnosed with syphilis and referred by their providers due to concerns for neurosyphilis. We evaluated 150 people with CSF abnormalities who were treated with either intravenous aqueous penicillin G (PenG) or intramuscular aqueous procaine penicillin G plus oral probenecid (APPG-P). An abnormal CSF diagnosis was defined as a white blood cell (WBC) count >20/µL, a CSF protein reading >50 mg/dL, or a reactive CSF-Venereal Disease Research Laboratory test (VDRL). Hazard ratios for normalization of CSF or serum measures were determined using Cox regression. In individuals treated with either PenG or APPG-P, CSF WBCs and CSF-VDRL reactivity normalized within 12 months after treatment, while protein normalized more slowly and less completely. There was no relationship between treatment regimen or human immunodeficiency virus (HIV) status and likelihood of normalization of any measure. Among those living with HIV, CSF WBC counts and CSF-VDRL reactivity were more likely to normalize in those treated with antiretrovirals. Unexpectedly, CSF WBCs were more likely to normalize in those with low CD4+ T cell counts. When neurosyphilis was more stringently defined as a reactive CSF-VDRL, the relationship with the CD4+ T cell count remained unchanged. In the current antiretroviral treatment era, neurosyphilis treatment outcomes are not different for PenG and APPG-P, regardless of HIV status. The relationship between the normalization of CSF WBC counts and CD4+ T cell counts may indicate continued imprecision in neurosyphilis diagnostic criteria, due to HIV-related CSF pleocytosis.

Suspected cutaneous anthrax in rural areas.

Cutaneous anthrax (CA), a zoonotic infectious disease is an important endemic public health disease in rural areas around the world, accounting for 95% of anthrax cases. Fifty patients with CA were diagnosed by the presence of characteristic skin lesions and positive response to treatment. Twenty-nine patients had been treated with oral ciprofloxacin or doxycyclin for 14 days and 21 patients had been treated with intramuscular procaine penicillin for 7 days. The demographic risk factors, characteristics and treatment of CA in rural areas were evaluated. The responses to two different systemic medications were compared using χ2 test. Twenty-two males and 28 females were included in this study. The predominant skin lesions were black eschar, ulcer and swelling of the skin. The predilection sites were the hand and fingers. The most common route of contamination for both male and female patients was handling raw meat. The most common occupation was housewife for female patients and animal industry for male patients. The patients under ciprofloxacin or doxycyclin administration responded better to treatment; pain at lesion site and new lesions at the time of treatment were significantly lower. Secondary infection appeared to be higher in patients under procaine penicillin administration, although this difference was not statistically significant. In rural areas that lack medical facilities with diagnostic tools, in the presence of black eschar, rapid diagnosis and treatment of CA is essential. The administration of a broad-spectrum antibiotic is recommended as the first line treatment of suspected CA.

Neurosyphilis: Knowledge Gaps and Controversies.

After reaching a nadir at the turn of the century, syphilis rates in the United States have increased since 2000. Treponema pallidum may disseminate to the central nervous system within hours to days after inoculation. In this review, we focus on knowledge gaps and areas of controversy in neurosyphilis epidemiology, diagnosis, and management. Modern estimates of the prevalence of neurosyphilis are hindered by the lack of consistent reporting data and are based on relatively small retrospective cohort studies. The various diagnostic modalities for neurosyphilis have significant limitations. Although several novel biomarkers for neurosyphilis have been evaluated, none to date have found a place in clinical practice. The role of a cerebrospinal fluid examination in patients without neurological symptoms continues to be an area of controversy, whereas the data for the use of antibiotic regimens other than intravenous aqueous or intramuscular procaine penicillin for the treatment of neurosyphilis are limited. As syphilis incidence continues to increase unabated in many countries around the world, it is critical to address these gaps of knowledge.

Two Regimes of Perioperative Antimicrobial Prophylaxis for Equine Castration: Clinical Findings, Acute-Phase Proteins, and Bacterial Cultures

A perioperative antibiotic for equine castration with second intention healing is controversial because the necessity is unclear and antimicrobial use promotes the selection of resistant bacteria. Information about different regimes for perioperative antimicrobial prophylaxis in equine castration is sparse. Goal of this study was to compare clinical findings, acute-phase proteins, and bacterial cultures in horses undergoing castration, treated with an intravenous single administration of penicillin G sodium (1× Pen group) or a 3-day course of daily intramuscular procaine penicillin (3× Pen group). Forty-eight stallions were castrated under general anesthesia using a closed technique, with second intention healing. Serum amyloid A (SAA) and fibrinogen were measured on days 0, 3, and 8. Body temperature, wound swelling, and drainage were recorded daily over 10 days. Bacterial swabs of the wound were taken on days 0 and 3. Scrotal swelling (P = .032), amount of drainage from the wound (P = .039), and body temperature (P = .013) on day 8 after castration were significantly higher in the 1× Pen group. The concentration of SAA and fibrinogen on day 8 was significantly higher in the 1× Pen group compared with the 3× Pen group (SAA: P = .049; fibrinogen: P = .035). β-Hemolytic Streptococcus spp. were found more frequently cultured in the 1× Pen group than in the 3× Pen group. Clinical and laboratory data indicate lower inflammatory reaction in the early postoperative period after three applications of penicillin compared with a single-administration. Further investigations evaluating the long-term outcome and potential development of antimicrobial resistant bacteria are needed.

Simplified antibiotic regimens for treatment of clinical severe infection in the outpatient setting when referral is not possible for young infants in Pakistan (Simplified Antibiotic Therapy Trial [SATT]): a randomised, open-label, equivalence trial.

SummaryBackgroundParenteral antibiotic therapy for young infants (aged 0–59 days) with suspected sepsis is sometimes not available or feasible in countries with high neonatal mortality. Outpatient treatment could save lives in such settings. We aimed to assess the equivalence of two simplified antibiotic regimens, comprising fewer injections and oral rather than parenteral administration, compared with a reference treatment for young infants with clinical severe infection.MethodsWe undertook the Simplified Antibiotic Therapy Trial (SATT), a three-arm, randomised, open-label, equivalence trial in five communities in Karachi, Pakistan. We enrolled young infants (aged 0–59 days) who either presented at a primary health-care clinic or were identified by a community health worker with signs of clinical severe infection. We included infants who were not critically ill and whose family refused admission. We randomly assigned infants to either intramuscular procaine benzylpenicillin and gentamicin once a day for 7 days (reference); oral amoxicillin twice daily and intramuscular gentamicin once a day for 7 days; or intramuscular procaine benzylpenicillin and gentamicin once a day for 2 days followed by oral amoxicillin twice daily for 5 days. The primary outcome was treatment failure within 7 days of enrolment and the primary analysis was per protocol. We judged experimental treatments as efficacious as the reference if the upper bound of the 95% CI for the difference in treatment failure was less than 5·0. This trial is registered at ClinicalTrials.gov, number NCT01027429.FindingsBetween Jan 1, 2010, and Dec 26, 2013, 2780 infants were deemed eligible for the trial, of whom 2453 (88%) were enrolled. Because of inadequate clinical follow-up or treatment adherence, 2251 infants were included in the per-protocol analysis. 820 infants (747 per protocol) were assigned the reference treatment of procaine benzylpenicillin and gentamicin, 816 (751 per protocol) were allocated amoxicillin and gentamicin, and 817 (753 per protocol) were assigned procaine benzylpenicillin, gentamicin, and amoxicillin. Treatment failure within 7 days of enrolment was reported in 90 (12%) infants who received procaine benzylpenicillin and gentamicin (reference), 76 (10%) of those given amoxicillin and gentamicin (risk difference with reference −1·9, 95% CI −5·1 to 1·3), and 99 (13%) of those treated with procaine benzylpenicillin, gentamicin, and amoxicillin (risk difference with reference 1·1, −2·3 to 4·5).InterpretationTwo simplified antibiotic regimens requiring fewer injections are equivalent to a reference treatment for young infants with signs of clinical severe infection but without signs of critical illness. The use of these simplified regimens has the potential to increase access to treatment for sick young infants who cannot be referred to hospital.FundingThe Saving Newborn Lives initiative of Save the Children, through support from the Bill & Melinda Gates, and by WHO and USAID.

Evaluation of cutaneous anthrax cases during an outbreak in the east region of Turkey.

Anthrax is a zoonotic infection caused by Bacillus anthracis. We aimed to retrospectively evaluate cutaneous anthrax cases that occurred during an outbreak in eastern Turkey (Hakkari-Yüksekova), where people mostly earn their living from animal husbandry. Forty-six cutaneous anthrax patients that were admitted to the hospital during a very short duration of 3 months (June-August 2011) were evaluated. Out of 46 patients, 27 (52%) were women and 19 (48%) were men. The mean age was 37 ± 13 years. The distribution of occupations was 1 butcher, 1 cook, 5 farmers, 27 housewives, 11 shepherds, and 1 teacher. Multiple lesions were seen in 7 patients (15%) and the rest of the patients had only 1 lesion. We observed significant clinical differences among the cases and noted which particular symptoms were associated with the various skin lesions. We treated our patients with intramuscular procaine penicillin or oral ciprofloxacin/doxycycline. Anthrax is an important health problem that can cause lethal outbreaks. Therefore, one should think about anthrax when faced with a patient with history of animal contact that has a painless ulcer with edema and/or vesicles, especially in endemic countries like Turkey.

Safety and efficacy of alternative antibiotic regimens compared with 7 day injectable procaine benzylpenicillin and gentamicin for outpatient treatment of neonates and young infants with clinical signs of severe infection when referral is not possible: a randomised, open-label, equivalence trial.

Severe infections remain one of the main causes of neonatal deaths worldwide. Possible severe infection is diagnosed in young infants (aged 0-59 days) according to the presence of one or more clinical signs. The recommended treatment is hospital admission with 7-10 days of injectable antibiotic therapy. In low-income and middle-income countries, barriers to hospital care lead to delayed, inadequate, or no treatment for many young infants. We aimed to identify effective alternative antibiotic regimens to expand treatment options for situations where hospital admission is not possible. We did this randomised, open-label, equivalence trial in four urban hospitals and one rural field site in Bangladesh to determine whether two alternative antibiotic regimens with reduced numbers of injectable antibiotics combined with oral antibiotics had similar efficacy and safety to the standard regimen, which was also used as outpatient treatment. We randomly assigned infants who showed at least one clinical sign of severe, but not critical, infection (except fast breathing alone), whose parents refused hospital admission, to one of the three treatment regimens. We stratified randomisation by study site and age (<7 days or 7-59 days) using computer-generated randomisation sequences. The standard treatment was intramuscular procaine benzylpenicillin and gentamicin once per day for 7 days (group A). The alternative regimens were intramuscular gentamicin once per day and oral amoxicillin twice per day for 7 days (group B) or intramuscular procaine benzylpenicillin and gentamicin once per day for 2 days, then oral amoxicillin twice per day for 5 days (group C). The primary outcome was treatment failure within 7 days after enrolment. Assessors of treatment failure were masked to treatment allocation. Primary analysis was per protocol. We used a prespecified similarity margin of 5% to assess equivalence between regimens. This study is registered with ClinicalTrials.gov, number NCT00844337. Between July 1, 2009, and June 30, 2013, we recruited 2490 young infants into the trial. We assigned 830 infants to group A, 831 infants to group B, and 829 infants to group C. 2367 (95%) infants fulfilled per-protocol criteria. 78 (10%) of 795 per-protocol infants had treatment failure in group A compared with 65 (8%) of 782 infants in group B (risk difference -1.5%, 95% CI -4.3 to 1.3) and 64 (8%) of 790 infants in group C (-1.7%, -4.5 to 1.1). In group A, 14 (2%) infants died before day 15, compared with 12 (2%) infants in group B and 12 (2%) infants in group C. Non-fatal relapse rates were similar in all three groups (12 [2%] infants in group A vs 13 [2%] infants in group B and 10 [1%] infants in group C). Our results suggest that the two alternative antibiotic regimens for outpatient treatment of clinical signs of severe infection in young infants whose parents refused hospital admission are as efficacious as the standard regimen. This finding could increase treatment options in resource-poor settings when referral care is not available or acceptable.

Simplified Antibiotic Regimens for the Management of Clinically Diagnosed Severe Infections in Newborns and Young Infants in First-level Facilities in Karachi, Pakistan

Infection in young infants is a major cause of morbidity and mortality in low-middle income countries, with high neonatal mortality rates. Timely case management is lifesaving, but the current standard of hospitalization for parenteral antibiotic therapy is not always feasible. Alternative, simpler antibiotic regimens that could be used in outpatient settings have the potential to save thousands of lives. This trial aims to determine whether 2 simplified antibiotic regimens are equivalent to the reference therapy with 7 days of once-daily (OD) intramuscular (IM) procaine penicillin and gentamicin for outpatient management of young infants with clinically presumed systemic bacterial infection treated in primary health-care clinics in 5 communities in Karachi, Pakistan. The reference regimen is close to the current recommendation of the hospital-based intravenous ampicillin and gentamicin therapy for neonatal sepsis. The 2 comparison arms are (1) IM gentamicin OD and oral amoxicillin twice daily for 7 days; and (2) IM penicillin and gentamicin OD for 2 days, followed by oral amoxicillin twice daily for 5 days; 2250 "evaluable" infants will be enrolled. The primary outcome of this trial is treatment failure (death, deterioration or lack of improvement) within 7 days of enrollment. Results are expected by early 2014. This trial will determine whether simplified antibiotic regimens with fewer injections in combination with high-dose amoxicillin are equivalent to 7 days of IM procaine penicillin and gentamicin in young infants with clinical severe infection. Results will have program and policy implications in countries with limited access to hospital care and high burden of neonatal deaths.

A lethal injection?

In October, 2010, a 29-year-old man initially presented to a primary care clinic with fevers, sore throat, and odynophagia, and was treated with oral phenoxymethylpenicillin 250 mg four times daily for tonsillitis. He re-presented 72 h later with persisting symptoms and fever of 38·4°C, and was administered 1 000 000 units of intramuscular procaine benzylpenicillin. 4–5 min later, he collapsed with no cardiac output, and cardio pulmonary resuscitation was commenced. Paramedic staff arrived within 20 min and monitoring showed ventricular fi brillation. Defi brillation was successful in achieving sinus rhythm with immediate return of spontaneous circulation. 12-lead ECG on arrival to hospital was unremarkable. The patient had no signs to suggest anaphylaxis and serum tryptase was normal. He was weaned off respiratory support in the intensive care unit and was transferred to the cardiology ward. He had no signifi cant medical history, including no atherosclerotic risk factors, prior syncope, or family history of premature sudden death. Concentrations of cardiac troponins were slightly raised. Echocardiography showed a structurally normal heart. Exercise stress testing was normal to a high workload with normal shortening of the QT interval, no evidence of ischaemia, and no arrhythmias. Cardiac MRI was abandoned because of claustrophobia. An electrophysiology study including ventricular stimulation was normal. Adrenaline provocation was unremarkable. Flecainide challenge showed a characteristic type 1 Brugada pattern with convex ST-segment elevation and T-wave inversion in leads V1–V3 (fi gure). An implantable cardioverter–defi brillator was inserted and

Oral antibiotics versus parenteral antibiotics for severe pneumonia in children

Acute respiratory infection (ARI) is one of the leading causes of morbidity and mortality in children under five years of age in developing countries. When hospitalisation is required, the usual practice includes administering parenteral antibiotics if a bacterial infection is suspected. This has disadvantages as it causes pain and discomfort to the children, which may lead to treatment refusal or reduced compliance. It is also associated with needle-related complications. In some settings this equipment is in short supply or unavailable necessitating transfer of the child, which increases risks and healthcare costs. To determine the equivalence in effectiveness and safety of oral antibiotic compared to parenteral antibiotic therapies in the treatment of severe pneumonia in children between three months and five years of age. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2005); MEDLINE (January 1966 to July 2005); EMBASE (January 1990 to July 2005) and LILACS (February 2005). The review included published or unpublished randomised controlled trials (RCTs) and quasi-RCTs comparing any oral antibiotic therapy with any parenteral antibiotic therapy for the treatment of severe pneumonia in children from three months to five years of age. The search yielded more than 1300 titles. Only three studies met all criteria for eligibility. One of the identified trials is yet to publish its results. We did not perform a meta-analysis because of clinical heterogeneity of therapies compared in the included trials. Campbell 1988 compared oral co-trimoxazole versus intramuscular procaine penicillin followed by oral ampicillin in 134 children. At the seventh day of follow up, treatment failure occurred in 6/66 (9.1%) in the oral co-trimoxazole group and 7/68 (10.2%) in the combined-treatment group. The risk difference was -0.01% (95% confidence interval (CI) -0.11 to 0.09). The APPIS Group 2004 evaluated 1702 patients comparing oral amoxicillin versus intravenous penicillin for two days followed by oral amoxicillin. After 48 hours, treatment failure occurred in 161/845 (19%) in the amoxicillin group and 167/857 (19%) in the parenteral penicillin group. The risk difference was -0.4% (95% CI -4.2 to 3.3). The authors reported similar recovery in both groups at 5 and 14 days. Oral therapy appears to be an effective and safe alternative to parenteral antibiotics in hospitalised children with severe pneumonia who do not have any serious signs or symptoms.

Chancre redux or reinfection? A case report in an HIV-positive man

An HIV-positive heterosexual man presented with a recurrent penile chancre, 20 months after treatment with intramuscular procaine benzyl penicillin. Was this a rare case of chancre redux (monorecidive) or re-infection?

Ocular syphilis: the new epidemic

To present the clinical presentation, diagnosis, and management of syphilitic uveitis in the context of an epidemic of syphilis in the UK. Retrospective clinical case series. Six new cases of syphilitic uveitis presented to the Manchester Uveitis Clinic in 2004, after a 15-fold increase in the incidence of syphilis in the UK, including 615 cases in Greater Manchester in the 5 years to 2004. Four cases had secondary syphilis, two had latent disease, two had no rash, and two were HIV positive. Ocular involvement included anterior or panuveitis, retinitis, retinal vasculitis, and papillitis. All resolved on treatment including intramuscular procaine penicillin G with oral probenecid. Syphilis is much more common recently and syphilitic uveitis should be considered in all patients with rash and/or headache, where there is retinitis and/or retinal vasculitis, or in any uveitis of uncertain origin. Treatment is that of neurosyphilis.

Síndrome de Hoigne

Background Hoigne's syndrome is a pseudoanaphylactic or pseudoallergic reaction that occurs after intramuscular administration of penicillin G procaine or benzathine. These are usually embolic toxic reactions possibly due to vascular occlusion by large crystals of the penicillin salts. We report a case of Hoigne's syndrome. Case report A 44-year-old woman received 1,200,000 U.I. of intramuscular procaine penicillin once daily for treatment of acute amygdalitis. Immediately after the second dose the patient developed mental confusion, visual and auditory hallucinations, perceived changes of body shape, swelling of the tongue and a fear of impending death. Penicillin allergy study (serum-specific IgE levels, skin tests and provocation test) was performed. The diagnosis of Hoigne's syndrome was confirmed by negative oral challenge test with penicillin. Conclusions Hoigne's syndrome is a pseudoanaphylactic reaction that must be differentiated from authentic anaphylactic shock due to penicillin. This distinction allows treatment to be continued in Hoigne's syndrome, whereas it is contraindicated in anaphylactic shock.

An unusual case of retinitis

A 35-year-old HIV positive man presented to casualty at Moorfields Eye Hospital in July, 1999, with a 10 day history of redness in the right eye and 3 days of reduced visual acuity and floaters. A diagnosis of conjunctivitis had been made and he was using topical chloramphenicol. He had been diagnosed as HIV positive in 1989 and developed Kaposi’s sarcoma of the hard palate in 1991, which was treated with radiotherapy and interferon. His medications were didanosine (400 mg per day), nevirapine (200 mg twice daily), delavirdine (600 mg twice daily), saquinavir (800 mg per day) and cotrimoxazole (960 mg thrice weekly+). His viral load was 91 000 copies/mL with a CD4 count of 320/ L. His lowest recorded CD4 count was 190/ L. Examination showed him to be myopic with corrected visual acuity of 6/9 on the right. His eye was injected, with moderate anterior chamber and vitreous inflammation. Retinal examination showed a large area of pallor superiorly with thin, finely pigmented retina peripherally (figure). The left eye was normal. Atypical viral retinitis was the provisional diagnosis. He had a biopsy sample of his vitreous taken, which was sent for culture, histology, and PCR of viral DNA. He was admitted and treated with 2 mg intravitreal gangiclovir and intravenous foscarnet (60 mg/kg thrice daily) to treat herpes viruses Cytomegalovirus (CMV), Varicella zoster virus (VZV), herpes simplex virus (HSV) which are the commonest causes of retinitis in patients with AIDS. Over the following days the edge of the retinal lesion advanced, however the periphery became atrophic. The results of viral DNA PCR were available 5 days later and were negative for HSV-1, HSV-2, CMV, VZV and Epstein Barr virus. Syphilis screening showed a positive TPHA and positive VDRL (1/256). IgG was detected, however IgM was not, suggestive of past treponemal infection, and the patient remembered having had treatment for syphilis 10 years previously with intramuscular procaine penicillin, but he had been lost to follow-up. With his optic nerve and macula under threat from spread of retinitis, he was treated with amoxycillin 3 mg twice daily and probenicid 1 g twice daily for 5 days, by which time the retinitis had stopped advancing and showed signs of healing with a return of visual acuity to 6/6. Further investigation of his clinical state and syphilitic status was then undertaken. When last seen in October, 1999, his eye was quiet with acuity of 6/6. CASE REPORT

Acceptability and compliance with daily injections of procaine penicillin in the outpatient treatment of syphilis-treponemal infection.

In the United Kingdom, it is recommended that syphilis should be treated with intramuscular daily procaine penicillin with or without oral probenecid for 8 to 21 days. However, it has been argued that this regimen would be unacceptable to patients in terms of daily attendance and volume of drug administered, resulting in poor compliance. To assess the acceptability of and compliance with daily procaine penicillin for 10 to 17 days in patients attending an East London Genito-Urinary Medicine Clinic with a diagnosis of syphilis-treponemal infection. The notes of 210 consecutive patients attending with syphilis-treponemal infection who had been offered treatment with daily procaine penicillin, with or without oral probenecid for 10 to 17 days, were reviewed retrospectively. Of 210 patients who were offered daily procaine penicillin, 42 (20%) declined and were given oral doxycycline, amoxicillin, or depot penicillin injections. Of 168 patients who accepted daily procaine penicillin, depending on the stage of infection, 90 (54%) had 1.8 g of daily procaine penicillin together with oral probenecid 500 mg every 6 hours for 17 days (high-dose regimen), 57 (34%) had 0.6 g of daily procaine penicillin for 10 to 17 days (low-dose regimen), and 21 (12%) had mixed-dose regimens ranging from 0.5 to 2.4 g. Of the 90 who had high-dose regimen, 76 (84%) complied with treatment compared with 50 (88%) of 57 who had low-dose regimen. All 21 patients who had mixed-dose regimens complied fully. Daily procaine penicillin is a well-accepted out-patient regimen with excellent compliance (88% overall) and minimal side effects. Because the high-dose regimen has been shown to achieve treponemicidal levels of penicillin in the cerebrospinal fluid, it is recommended for patients with neurosyphilis or those in whom neurosyphilis cannot be excluded. It also could be considered for patients with concomitant human immunodeficiency virus infection in view of the possible progression to neurosyphilis in those treated with depot penicillin.

The role of procaine in adverse reactions to procaine penicillin in horses

Procaine penicillin is a commonly used antibiotic in equine medicine but its use is associated with a substantial incidence of adverse reactions. Soluble procaine concentrations were determined by HPLC in several commercially available procaine penicillin preparations, including some that were involved in adverse reactions. The mean (+/- SEM) soluble procaine concentrations in the veterinary preparations was 20.18 +/- 5.07 mg/ml, which was higher than the concentration in the only procaine penicillin preparation for use in humans in Australia of 7.3 mg/ml. Heating the veterinary procaine penicillin preparations to 50 degrees C for 1 day led to a significant (P less than 0.01) increase in the amount of soluble procaine. Heating to 50 degrees C for 7 days also produced a significant (P less than 0.02) increase. Soluble procaine tended to return to baseline concentrations when veterinary procaine penicillin preparations were heated to 50 degrees C for 2 days then stored for 7 days at room temperature. Administration of procaine HCl intravenously (IV) at 2, 5, and 10 mg/kg produced behavioural, locomotor and vascular reactions, which were clinically similar to those reported in adverse reactions to procaine penicillin. The more severe reactions occurred at higher doses, although different horses responded variably at the same dose. Some adverse reactions lead to recumbency but none were fatal. The blood procaine concentrations 1 min after IV administration averaged 19.0 +/- 12.6 and 25.3 +/- 16 micrograms/ml at 2.5 mg/kg and 5 mg/kg, respectively. Ten min after administration, blood procaine concentrations were significantly higher (P less than 0.001) in the 5 mg/kg group than in the 2.5 mg/kg group. Intramuscular (IM) procaine HCl at 5 mg/kg produced significantly lower (P less than 0.001) blood concentrations than similar IV doses, and, in contrast to the IV doses, the amount of procaine in the blood was significantly higher 5 and 10 min after administration than it was after 1 min. Mild excitatory reactions in 4/5 horses were noted 5 to 10 min after IM administration. Administration of diazepam 20 s before procaine HCl prevented the excitatory adverse reaction in 2/2 horses, but administration after the procaine did not influence the outcome.