Rapid method for estimating the risk of acutely controversial side effects of prescription drugs.
When controversy suddenly erupts about the risk of using a prescription drug, there is an urgent need for fast methods of risk estimation. Some unexpected side-effects of prescription drugs are indications for the prescribing of another kind of drug. If the risk of such a side-effect is high, it should be reflected in clustered prescribing of the side-effect-alleviating drug in sequence with the side-effect-causing drug. The risk of drug-attributable side-effects can be estimated by comparing average incidences of initial prescriptions for the side-effect-alleviating drug before, during, and long after the dispensing of the presumed side-effect-causing drug. We monitored computerized, complete drug dispensing records of anonymous outpatients for use of flunarizine, an anti-vertigo/anti-migraine drug that case reports had suggested causes mental depression and/or Parkinsonism. Among 1284 patients who eventually got flunarizine during a 31 month period, 1 in 7 was started on an anti-depressant before or long after flunarizine; only 1 in 82 might be said to have been started on an anti-depressant because of flunarizine. There was no evidence that anti-Parkinson drugs were started because of flunarizine, though the numbers are small. The analysis takes only a few days, and can help set bounds on risks of the subset of adverse drug reactions that are themselves indications for use of other drugs.
Petri
H
H
Department of Epidemiology, University of Limburg, Maastricht, The Netherlands.
Leufkens
H
H
Naus
J
J
Silkens
R
R
van Hessen
P
P
Urquhart
J
J
D000368:Aged; D000928:Antidepressive Agents / Q000008:administration & dosage / Q000627:therapeutic use; D000978:Antiparkinson Agents / Q000008:administration & dosage / Q000627:therapeutic use; D003863:Depression / Q000139:chemically induced* / Q000188:drug therapy; D011307:Drug Prescriptions / Q000706:statistics & numerical data; D005260:Female; D005444:Flunarizine / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010302:Parkinson Disease, Secondary / Q000139:chemically induced* / Q000188:drug therapy; D010594:Pharmacies; D012307:Risk Factors; D013997:Time Factors
D000928:Antidepressive Agents; D000978:Antiparkinson Agents; D005444:Flunarizine