Recently, I was asked to be an expert witness for a case involving a patient who experienced an adverse drug reaction and sued the prescriber and pharmacist for not warning them of their risks. This caused me to reflect on my own practice and my responsibilities to counsel and educate patients about their medications so that they can make informed decisions. Recently, I was asked to be an expert witness for a case involving a patient who experienced an adverse drug reaction and sued the prescriber and pharmacist for not warning them of their risks. This caused me to reflect on my own practice and my responsibilities to counsel and educate patients about their medications so that they can make informed decisions. Case 1: A pharmacist received a prescription for sulfamethoxazole/trimethoprim 800 mg/160 mg twice daily for 10 days. Before filling the prescription, the pharmacist reviewed his records and saw that the patient had an allergy to sulfa antibiotics, but he was not sure about the type or severity of the reaction. The pharmacist called the prescrib- er, who told the pharmacist that she was aware of the allergy but believed the antibiotic was the patient’s best option. The pharmacist made a note to talk with the patient about the allergy.■Pharmacists should fully inform patients about their treatment.■Pharmacists should document patient care activities and seek out complete medical histories. ■Pharmacists should fully inform patients about their treatment.■Pharmacists should document patient care activities and seek out complete medical histories. Case 2: A pharmacist was providing medication therapy management services for a new patient, an older man with dementia whose daughter held his power of attorney. The daughter noted that her father’s past medical history was significant for atrial fibrillation, coronary artery disease, hyertension, and hyperlipidemia and that her father had recently moved from another state. The pharmacist saw that the patient and his daughter did not maintain very good medical histories. The patient had not yet established a relationship with a lowith his daughter’s physician next week. The pharmacist noted that the patient took simvastatin 80 mg and extended- release diltiazem 180 mg every day. These cases represent real dilemmas pharmacists face in informed consent and duty to warn. For my recent work as an expert witness, I reviewed the literature regarding informed consent and found an interesting article.1.Wick J.Y. Zanni G.R. Informed consent: what every pharmacist should know.J Am Pharm Assoc. 2001; 41: 523-527Scopus (2) Google Scholar ■From 30% to 50% of patients do not use medication as prescribed because they lack information.■Pharmacists have a professional obligation to counsel patients so that they are informed comanagers of their drug therapy.■Informed consent is an interactive process with patients through which the pharmacist ensures that they fully understand their medications.■Informed consent requires pharmacists to be knowledgeable about treatment risks and benefits and standards of care.■Obstacles to informed consent occur when communication barriers exist between pharmacists and other health care providers and/or between pharmacists and patients.■Uninformed pharmacists result in uninformed patients and failure to meet informed consent guidelines. In the first case, the pharmacist has a responsibility to seek more information about the patient’s previous allergic reaction. After obtaining that information, the pharmacist must communicate with the prescriber to ensure that she has the same information. If the prescriber still wants the patient to receive the antibiotic, then the pharmacist has a responsibility to inform the patient of the risks. As pharmacists, we must both follow prescribers’ orders and fully inform patients about their treatment. Informed patients have the right to refuse treatment even if it is in their best interest. Pharmacists need to routinely document patient care, including recommendations, education, and follow-up. In the second case, a pharmacist with incomplete information was presented with two potential problems—a dosage issue with simvastatin and a drug-drug interaction between simvastatin and diltiazem. This pharmacist was not filling prescriptions, but rather providing a professional service. The patient and caregiver provided incomplete medical histories, so the pharmacist was not able to assess their medications properly. The pharmacist should, if possible, obtain a complete medical history from previous health care providers, including when medications were started, reasons for current doses, and any monitoring data. If that information is not available, then the pharmacist should address the potential problems with the patient and caregiver and send a written work-up to the new physician. Again, the pharmacist should fully document this information in the patient chart. Pharmacists may not always have complete medical histories, but that does not preclude them from informing their patients and other providers of potential drug therapy problems. Not only is this consistent with good patient care—it is the right thing to do.