A Personal Experience With Side Effects

We’d prefer not to know that all drugs (all of them) are potentially poisonous. Check this out by reading the “overdose” section of the lengthy version of the package insert accompanying your prescription. We don’t set out to intentionally overdose ourselves on common pharmacologic selections–meds for blood pressure, diabetes, birth control, anxiety, sleep, and so forth. However, what helps one person might make the next seriously ill or even kill her. Sauce for the goose may be no sauce for the gander.

Although it’s chilling to ponder that correctly taken prescription drugs may be the fourth leading cause of death in the US, let’s focus instead on the side effects of your prescription.

It helps to understand the whole-body effects of any drug by reading the complete list of side effects on the longer, unabridged package insert, which you may have to ask the pharmacist to provide. It’s organized first by body systems, like cardiovascular, gastrointestinal, and musculoskeletal, and then by individual symptoms reported during clinical trials.

For example, the gastrointestinal category might include nausea, vomiting, diarrhea, and so forth. Continue reading and you’ll see a section labeled “post-marketing experience.” These are the side effects that didn’t appear during the trials but were reported by doctors or patients after the drug hit the market and started being taken by the masses.

Most patients prefer the short version of the side-effect list, the one that’s usually dispensed with the med. It sidesteps some of the scary stuff. Big Pharma wants you to approach their product with a positive mental attitude. But reading the complete side-effect list will give you an idea of how a drug works, affecting (for better or worse) every system in your body. Big Pharma and most doctors want you to believe that the single beneficial action a chemical will produce makes everything else worthwhile. The “everything else” is not beneficial and euphemistically labeled side effects.

All drugs–every one of them–can cause side effects

The cardinal rule of medication prescribing, learned in medical school but too often forgotten by physicians, is this: any new and otherwise unexplained symptom that seemed to begin after a medication was started is most likely a side effect. Unfortunately, doctors usually order a bunch of tests attempting to diagnose a new symptom rather than asking “Could this have started after you took a new medication?” And “new medication” applies to pretty much anything– prescription drugs, over-the-counter meds, nutritional supplements, herbs, anything.

Among all the drugs available, it’s the ones that affect your brain that carry the longest list of side effects. This group includes antidepressants, tranquilizers, and sleep meds. Like the little girl who had a little curl right in the middle of her forehead, when they work, they’re very good indeed, but when they’re bad they’re horrid.

The sleep aids are especially problematic. Ambien (zolpidem), for example, is notorious for triggering nighttime sleepwalking and activities totally forgotten the next morning. The very funny Ambien Cookbook offers recipes for users under the influence. Less amusing is novelist Philip Roth’s encounter with the now little-used sleep med Halcion, which triggered behavior so bizarre his family considered psychiatric hospitalization.

An insomniac doctor tests a new sleep drug on himself

As a lifelong insomniac, I’ve never had much luck with sleeping pills. Happily, I’ve never experienced any side effects either. However, I was intrigued by the newly released Silenor (doxepin) because it was completely unrelated to the Ambien/Lunesta/Sonata family. Doxepin is classified as a tricyclic antidepressant and has been around for almost 40 years, marketed as Sinequan. Its main side effect is drowsiness, and because users walked around like zombies, Sinequan fell out of favor when the non-sedating SSRIs like Prozac became available. The usual antidepressant dose of Sinequan was around 100 mg, which caused patients to stop complaining about depression because they fell asleep during therapy.

But Big Pharma is always on the prowl to capitalize on the side effects of an old, FDA-approved drug to treat something new. Pernix Therapeutics, one of the smaller players, specializes in this. Change the dose ever so slightly and you’ve created a new drug with a new price. 10 mg of generic doxepin costs 20 cents. One tablet of the new sleep med Silenor, containing 6 mg of doxepin, costs $11. (Yes, you could shake out some of the doxepin from the 10-mg capsule and make your own Silenor.)

So a few weeks ago when the charming Pernix drug rep dropped off a several boxes of Silenor samples (not being a controlled drug, this is allowed), I figured I’d give it a try before prescribing it. Yes, it worked. I slept, and fairly decently, with some rich but not particularly disturbing dreams. I felt pretty good the next day.

But within a week, I noticed that I felt distinctly unwell and simply did not make a connection with the Silenor. I was lightheaded, especially if I stood up too quickly (called orthostatic hypotension), my heart beat rapidly (tachycardia), and I was becoming out of breath just climbing a flight of stairs (breathlessness).

“This is not me,” I thought. Then I carefully took my pulse.

“Good heavens! I’m in atrial fibrillation.”

Afib, as it’s called in shorthand, is a common heart rhythm abnormality that’s generally not hard to treat, but it can lead to serious complications (like a stroke) if left alone. I’d have to give my cardiologist friend Dr Sukhjit Gill a call.

It was a weekend, and like everybody else I hoped my symptoms would just go away. Inexplicably (and not that I suspected the afib was connected to the sleep drug), I didn’t take the Silenor that weekend. The next day I felt fine. My afib, breathlessness, and lightheadedness were gone.

“Hmm.” I said, remembering how the tricyclic antidepressants, including doxepin, had been linked to heart rhythm abnormalities, but usually in doses much higher than the 6 mg in a Silenor. Nevertheless, everyone is biochemically unique, and maybe my heart had no liking for even a small amount of the stuff.

The Silenor package insert makes no mention of heart rhythm issues, blood pressure changes, and so forth. But the larger-dose Sinequan insert repeatedly warns doctors of these side effects. With a Google search, I hit pay dirt, with estimates that more than 3% of doxepin users reported atrial fibrillation, orthostatic hypotension, and breathlessness with even small doses.

“Well, that was certainly interesting,” I said to myself, already planning to return the remaining Silenor samples to the rep and file a drug reaction report with the FDA.

Key take-aways

Keep these ideas foremost in mind:

• Prescription drugs are valuable tools, but they’re essentially poisons with one or two positive effects. Use them only when absolutely necessary.
• If you develop an unfamiliar symptom, think carefully about any med you may have started taking. The connection is often not obvious. Statins for cholesterol can cause muscle pain, ACE inhibitor blood pressure meds can make you cough, quinolone antibiotics can rupture your Achilles tendon, and hydrochloroquine for rheumatoid arthritis can affect your color vision.
• If your doctor says “it can’t be a side effect,” use Google to verify. Insert the drug name and side effect into the search bar. Visit chat rooms to read what other patients are saying.
• When a Big Pharma drug commercial comes on TV, crank up the volume as they start listing side effects. This will remind you (again) that correctly taken prescription drugs are the fourth leading cause of death in the US.

Now that I have made you thoroughly nauseated…

Be well,
David Edelberg, MD