A 30-year-old woman underwent laparotomy and was placed on a seven-day course of metronidazole and ampicillin postoperatively. Chloroquine therapy for malaria was instituted on the sixth day and the patient developed acute dystonic reactions after a single dose. Diphenhydramine therapy before chloroquine administration did not prevent the development of the dystonic reactions. The extrapyramidal symptoms subsided upon diazepam administration and chloroquine withdrawal even though metronidazole therapy was continued. The mechanism of this adverse drug reaction based on the pharmacodynamic interaction between chloroquine and metronidazole is discussed. It is suggested that the combination of pyrimethamine and sulfadoxine be used in place of chloroquine for malaria chemotherapy in patients on metronidazole therapy.

Ivermectin is a macrocyclic lactone (fermentation) product and actinomycete (Streptomyces avermitilis) that possesses an unusually broad spectrum of potent activity against several species of nematodes, arachnids, and insects that parasitize domestic animals. From clinical trials in humans it has been found to be microfilaricidal, killing microfilariae of Onchocerca volvulus (the parasite causing onchocerciasis), and interrupting its transmission by the black fly vector. Dermal microfilariae density in patients are reduced to near zero levels for 6-12 months after a single oral dose of ivermectin 0.15-0.2 mg/kg. Its precise mechanism of action is unknown. It has a time to maximum concentration of 2.7-4.3 h, and an elimination half-life of 28 +/- 10 h. When compared with an oral solution the tablet dosage form has a relative bioavailability of approximately 60 percent. Not much is known about its metabolism in humans, and the unchanged drug is not detected in the urine. Controlled clinical trials have shown ivermectin to be associated with milder side effects than diethylcarbamazine, the current drug of choice for onchocerciasis therapy. It does not cause the severe Mazzoti-type (anaphylactoid) reactions that are associated with diethylcarbamazine use. Ivermectin is effective, safer, and more tolerable than diethylcarbamazine. It should, therefore, replace diethylcarbamazine as the drug of choice for onchocerciasis therapy.

The types and frequency of questions asked of clinical pharmacists introducing clinical pharmacy services in the internal medicine wards of a Nigerian university hospital and the degree of compliance with pharmacists' recommendations were studied. Three faculty pharmacists collected data in two 30-working day study periods, separated by a year. Totals of 197 questions (an average of 6.57 +/- 1.33 questions/working day) and 271 questions (an average of 9.03 +/- 1.10 questions/working day) were answered by the pharmacists in the first and second study periods, respectively. Pharmacists recommended changes in patient-specific drug therapy that were implemented 52 percent and 69 percent of the time in the first and second study periods, respectively. The most common type of drug information request concerned the presence or the likelihood of an adverse drug reaction. Continuous interaction between pharmacists and physicians in the patient-care setting results in a better appreciation of the pharmacist's role as drug information consultant, and the consequence of this is a high degree of compliance with pharmacists' recommendations.