Feeling Good: The New Mood Therapy (66 page)

To make things even more confusing, there are ether cases where a larger dose costs substantially more and you can save money by taking a smaller size. For example, take another look at the costs of desipramine on page 518. You will see that a hundred 75-mg desipramine pills cost $12.42, and that a hundred 150-mg desipramine pills cost $109.95 (again, because of different manufacturers). So you can save lots of money by taking two 75-mg pills instead of one 150-mg pill. Again, this is because different companies manufacture the 75-mg and 150-mg sizes. This may strike you as odd, but the pricing structure in some instances is completely out of whack.

Table 20–1
. Names, Doses, and Costs of Antidepressant Medications

^a
If your doctor prescribes the chemical or “generic” name on the prescription, your pharmacist can often substitute an inexpensive brand that can be much less costly than the trade-name drugs.

^b
Only the brand name of the original drug is listed. Generic versions of these drugs have their own brand names.

^c
Cost source:
Mosby’s GenRx. 1998 (8th Edition): The Complete Reference Guide for Generic and Brand Drugs
. St. Louis: Mosby. The average wholesale price for 100 pills of the least expensive brand currently available is listed. This is the price your local retail pharmacist would have to pay for the product without any special discounts. Your cost will be more and will depend on the markup by your pharmacist.

^d
The doses would be used for the treatment of an episode of depression. Some patients may benefit from doses higher or lower than the normal range. If prolonged treatment is necessary following recovery, a smaller dose may be sufficient. Always consult with your doctor before changing the dose.

^e
These are drugs with generic brands available in 1998. More of the current antidepressant drugs will become available as generic brands when their original drug patents expire.

^f
Maprotiline should not exceed 175 mg per day if a patient is kept on the drug for an extended period. The manufacturer suggests that the dose should not exceed a maximum of 225 mg for periods of up to six weeks.

^g
The doses of several mood stabilizers must be monitored by blood tests and will therefore be highly individualized for each patient, depending on your age, gender, weight, diagnosis, and individual metabolism, as well as other medications you may be taking.

^h
Higher doses may be required during acute mania because the body appears to metabolize lithium more rapidly during manic episodes.

ⁱ
This is also available as Depakote Sprinkle (125 mg), which can be sprinkled onto food.

^j
The price of the 25 mg Lamictal was not listed in
Mosby’s GenRx
(1998 edition).

^k
This is the recommended dose range for epilepsy when given in conjunction with valproic acid. When given alone, the recommended dose range for epilepsy is 300 mg to 500 mg per day.

If you or a family member is taking an antidepressant, make sure you study Table 20–1 and discuss these cost issues with your druggist. A little quick and easy research on your part may result in large savings.

Another important point, not illustrated in the table, is that the cost of the same generic drug and dose can vary greatly because the generics often have so many different manufacturers. In Table 20–1, I have always listed the least costly generic brand of each pill; other more costly versions of the same pill are not listed. For example a hundred 50-mg imipramine pills manufactured by the drug company HCFA FFP will cost only $3.08. Because this was the lowest-priced generic brand, I listed it in Table 20–1. In contrast, a hundred of the same size imipramine manufactured by Novartis, another drug company, will cost $74.12—more than twenty times more. Keep in mind that if your doctor prescribes the antidepressant by its chemical name (as listed in Table 20–1), your druggist will have the freedom to provide you with the least costly generic brand if one is available.

My goal is not to promote any one drug or class of drug. All antidepressants have merit, and they all have some drawbacks. The key point is this: more expensive does not always mean better. If you review the costs of these drugs, you can work with your doctor and pharmacist to choose the medication and brand that will make the most sense for you.

The first drugs listed in the Table of Antidepressants on page 514 are called “tricyclic” and “tetracyclic” antidepressants.
The tricyclic and tetracyclic antidepressants differ slightly in their chemical structures. “Tri” means three and “tetra” means four. “Cyclic” refers to a circle or ring. The tricyclic compounds consist of three linked molecular rings, while the tetracyclics consist of four.

You will see that eight tricyclic and two tetracyclic antidepressants are listed in the Table of Antidepressants. The eight tricyclic drugs include amitriptyline (Elavil), clomipramine (Anafranil), desipramine (Norpramin), doxepin (Sinequan), imipramine (Tofranil), nortriptyline (Aventyl), protriptyline (Vivactil), and trimipramine (Surmontil). These eight tricyclic drugs used to be the most widely prescribed antidepressants. They are still among the most effective of all the antidepressants. Many of them are also the least expensive because generic brands have become available. However, tricyclics tend to have more side effects than the newer drugs, and so they are less popular than they used to be. By the same token, they have been prescribed for several decades and have a long track record of reasonably good effectiveness and safety.

The two tetracyclic antidepressant medications listed on the table are called amoxapine (Asendin) and maprotiline (Lu-diomil). These two tetracyclics were synthesized and released after the tricyclics had been in use for some time. It was hoped that they would represent significant improvements in treatment, either because of increased effectiveness for certain types of depression, or because of fewer side effects.

Unfortunately, these expected improvements did not really materialize. For the most part, the effectiveness, mechanism of action, and side effects of the eight tricyclic and the two tetracyclic antidepressants are quite similar.

Doses for the Tricyclic and Tetracyclic Antidepressants
. Table 20–1 on pages 518–523 lists the costs and dose ranges of the eight tricyclic and the two tetracyclic antidepressant medications. As noted above, many of them are inexpensive because they are no longer on patent, and so generic brands are readily available. Don’t be fooled into
thinking the cheaper antidepressants are less effective, however. A number of studies suggest they may be slightly more effective than many of the newer antidepressants such as Prozac.

The most common error your doctor is likely to make is to prescribe a dose of a tricyclic antidepressant that is too low. This statement may run against your grain if you feel you should take the lowest dose possible. In the case of tricyclics, if the prescribed dose is too low, the medication will not be effective. If you insist on taking a dose that is too low, you may be wasting your time. It simply will not help you. On the other hand, dosages above those recommended in Table 20–1 can be dangerous and may lead to a worsening of your depression.

Having said that, let me also say that there are cases in which people do respond to doses that are smaller than those listed (especially the elderly), and there are also times when people may need larger doses. One reason for this is that there can be considerable differences in how rapidly people metabolize antidepressant drugs. These differences are partially genetic, and are due to levels of certain enzymes in your liver, as described previously. If you are a “fast meta-bolizer” you will need a larger dose to maintain an effective blood level, and if you are a “slow metabolizer” you will need a smaller dose. In addition, you will learn below about other drugs that can make tricyclic blood levels fall and lose their effectiveness or increase and become more toxic.

If you suspect you may be taking an inappropriately large or small dose, review the dose ranges in Table 20–1 and discuss your concerns with your physician. Blood-level testing for most of the tricyclic antidepressants is readily available, so your doctor may order a blood test to make sure that the dose you are taking is neither too high nor too low for you.

The best way to begin taking a tricyclic medicine is to start out with a small dose and to increase the amount each day until a dose within the normal therapeutic range is achieved. This buildup can usually be completed within one
or two weeks. For example, a typical daily dose schedule for imipramine, one of the most commonly prescribed tricyclic antidepressant drugs listed in Table 20–1, might be the following: