Different people, different antidepressants

The prescription drug market is awash in medications marketed
for the treatment of depression with what could be as many as 30
common prescriptions on the market today, said Dr. Shan Crockett, a
Santa Cruz psychiatrist who assists with a Hollister-based
geriatric mental health program two days per week.
The prescription drug market is awash in medications marketed for the treatment of depression with what could be as many as 30 common prescriptions on the market today, said Dr. Shan Crockett, a Santa Cruz psychiatrist who assists with a Hollister-based geriatric mental health program two days per week.

And while a wide variety of options are available, selecting the right prescription for each patient is a balancing act that takes into account symptoms, state of mind and family history before signing off a prescription.

“Some depressions are really agitated and some are really slow,” said Crockett. “We would think about that, about whether there was a sleep problem involved or whether there were other things going on.

“When folks are very depressed, they still want to have sex. They come in and say, ‘Is this going to affect my drive?’ The other thing is ease of administration. Is it once a day? Three times a day? Do you go up in dosage once or is it a long process?”

Health professionals attempt to use the answers to all of these questions in selecting a prescription for any potential patient, but family history can be the strongest predictor of what will work best.

First degree family members, such as parents or siblings, are likely to have a good experience with the same types of drugs that will be right for the patient, said Crockett, but efficacy is not guaranteed.

“If I gave the same drug to 10 people, eight would be able to tolerate it, and of the two who had side effects, one would decide to stay with it for the benefits,” said Crockett. “Of those 10, six would actually be helped.”

Most of the time, Crockett gets his most effective results by using side effects to a patient’s advantage. For instance, he’ll use a sleep-inducing anti-depressant administered at bed time for patients with insomnia, and the bevy of choices he’s offered today give him a lot more options in prescribing such drugs.

Prior to 1988, two classes of antidepressant drugs existed – tricyclic antidepressants and monoamine oxidase inhibitors, commonly known as MAOIs – but both had significant drawbacks.

When taken according to prescription, tricyclics were both safe and effective, but in overdose, they often triggered cardiac arrhythmia, which made any overdose more likely to be fatal. Drugs under this classification included desipramine, imipramine, amitriptyline and doxepin.

On the other hand, MAOI’s like phenelzine, tranylcypromine and isocarboxazid didn’t offer users much fun. They included strict dietary guidelines that clamped down on the ingestion of fermented foods like wines, cheeses and other yummy items.

“The big revolution started in 1988, when Prozac came out,” said Crockett. “Prozac, whose generic is fluoxetine, was the first in a class called SSRI’s: Selective serotonin reuptake inhibitors. Basically, all of these antidepressants affect the neurotransmitters, which are chemicals in the brain. There are maybe 30 or 40 of them, but with modern classes of drugs, we are affecting maybe two or three: serotonin, norepinephrine and dopamine, all of which are connected to mood.”

Common prescriptions today almost unfailingly fall into this category. From the social anxiety medication Paxil to antidepressants like Lexapro, Celexa, Zoloft and Luvox, they help the body effectively make use of limited supplies of serotonin, a chemical associated with mood.

For ease of use, this set of prescriptions also takes the cake. However, users must wait at least six weeks to determine if the medication is working, and SSRI’s can have disturbing side effects such as depressed libido in men and women, as well as poor ejaculation control and impotence in men, according to manufacturers.

“The SSRI’s basically work on the serotonin alone, and we have other drugs that work on other brain chemicals,” said Crockett, who noted that an even newer class of drugs called SNRI’s for selective serotonin norepinephrine reuptake inhibitors, are gaining on the market as well. This set includes Effexor and Cymbalta, and works on the same brain chemicals as older tricyclic medications without the same risks, said Crockett.

Other drugs, such as the popular antidepressant Wellbutrin, are in a class of their own, as they don’t readily correspond to anything else on the market.

“We think Wellbutrin effects norepinephrine and dopamine,” said Crockett. “Remeron is also its own class.”

Wellbutrin is best suited for melancholic, low-energy depressions that lead to somewhat vegetative behavior, while Remeron is better indicated for someone with an agitated depression and insomnia, said Crockett.

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