Q. You have warned against taking cough syrup containing dextromethorphan while taking Paxil, Zoloft or similar antidepressants. My pharmacist sister insists that dextromethorphan is dangerous only when taken with MAO-inhibitor drugs and is safe with Paxil or Zoloft.
My elderly father is taking Paxil and I am in a quandary. Where can I find information to settle this problem and protect my father’s health?
A. An article by Donald Arnold, MD, in the December 2002 issue of Pediatrics in Review documents the interaction between antidepressants like Paxil or Prozac and the cough medicine dextromethorphan. When people combine dextromethorphan (the DM in Robitussin DM and similar products) with Prozac-like drugs the result can be “serotonin syndrome.” Symptoms can include anxiety, confusion, fever, sweating, agitation, muscle twitching, tremor and heart palpitations.
Q. Several doctors and pharmacists have told me not to drink grapefruit juice while taking medications, but they have not mentioned which prescriptions could be troublesome. My husband and I love grapefruit and share a fresh one each morning while they are in season. He takes Verelan at bedtime for hypertension, along with Pravachol for cholesterol. I take Estrace and Synthroid an hour before my breakfast and Xanax at bedtime to fall asleep.
I am confused about how long I should wait before eating grapefruit or drinking grapefruit juice. Where can I get a list telling which drugs are affected by grapefruit?
A. Not all medications interact with grapefruit. Pravachol, for example, does not, although other cholesterol drugs like Lipitor, Zocor and Mevacor are affected. Most blood pressure drugs are safe with grapefruit, but some like verapamil (Verelan, Calan, Covera, Isoptin), nifedipine (Procardia) and felodipine (Plendar) can be a problem.
Blood levels of estrogen, found in birth control pills and in your hormone replacement Estrace, are higher in the presence of grapefruit. So are sleeping pills or anxiety drugs like alprazolam (Xanax), triazolam (Halcion), diazepam (Valium) and Buspar (buspirone).
We are sending you our Guide to Grapefruit Interactions with more details. Anyone who would like a copy, please send $2 in check or money order with a long (no. 10) stamped, self-addressed envelope: Graedons’ People’s Pharmacy, No. J-91, P. O. Box 52027, Durham, NC 27717-2027.
The grapefruit effect can linger up to 24 hours or more, so waiting just two hours won’t solve the problem.
Q. You’ve suggested that most senior citizens buying Canadian medicine don’t realize they’re breaking the law. That’s not true. Most of them are well aware importing drugs is against the law, but it’s the only way they can afford the medicine they need to stay alive and well.
The news of the government cracking down on seniors is very disturbing. Without lower prescription prices, tens of thousands of people will get sicker and many will die needlessly.
A. It is unlikely that the FDA will start arresting senior citizens. But the agency has announced that it will be enforcing the law with special attention to organizations that facilitate importation of drugs from abroad. FDA doesn’t regulate prescription drugs prices, but legislation adding a drug benefit to Medicare could ease the strain for many seniors.