Setting Your Dosage
In This Chapter
- The trial-and-error process
- Avoiding extreme dosages
- Converting dosages among different thyroid medications
- True tales of underdosing and overdosing
- Taking your medication without fail
Chapter 8 helped you choose your thyroid medication. Your final step to health is deciding precisely how much medication you need. If you don’t take enough medication, you’ll continue having hypothyroidism symptoms. But if you take too much medication, you’ll become hyperthyroid, which is a much more dangerous illness (see Chapter 10).
This chapter explains what you need to know to avoid undesirable extremes and arrive at the dosage that’s perfect for you.
Finding Your Perfect Dosage
Discovering precisely the right amount of thyroid medication you need is a process of educated guesswork and trial and error, with your symptoms and blood tests as ways of continually checking on whether a particular choice is closer to or further from your optimal dosage.
The first factor to consider is your weight. A very rough rule of thumb is that your body needs one microgram (mcg) of T4, or its equivalent, per pound (up to 300 pounds). That means an adult weighing 200 pounds will need roughly 175-225 mcg of total thyroid hormones, while an adult weighing 150 pounds will need roughly 125-175 mcg.
The other key factor is how much help your thyroid actually needs. For example, if you’re in the early stages of thyroid disease, you might require just a little bit of medication to make up for your thyroid’s moderate underactivity. However, your doctor may have to gradually increase your dosage over time if your thyroid grows progressively worse.
As another example, if your hypothyroidism is due to external factors—such as a toxin interfering with your thyroid’s functioning, or a lack of iodine or selenium—your doctor might prescribe a substantial amount of thyroid medication at first, but taper it down as the cause of the problem is resolved.
Then again, if your thyroid has entirely stopped working, or has been surgically removed, your medication will need to take the place of all the hormones a thyroid normally supplies. The good news is there isn’t much of a practical difference be-tween being on lower or higher dose pills—they typically cost the same, are around the same size, and have the same rules (take them first thing in the morning with nothing but water). There’s even a distinct advantage to fully replacing a shut down or missing thyroid with medication, which is that once you determine the dosage that’s right for you, it’s unlikely to change. This means unless you notice symptoms returning—or new symptoms—you won’t need to have your thyroid hormone levels checked more than once a year.
You and your doctor can determine to what extent your thyroid needs help via two diagnostic tools: your thyroid blood tests (see Chapter 7) and your symptoms (see Chapter 6).
After studying the results of your initial blood tests, your doctor will prescribe her best guess for an appropriate dosage. She’ll err on the low side, because there’s no danger to your being slightly hypothyroid, while there are serious hazards associated with long-term hyperthyroidism, including heart damage and bone loss. For this reason your doctor will ask you to be alert for hyperthyroidism symptoms, such as a rapidly beating heart, acute anxiety, or simply feeling like you drank a pot of coffee when you didn’t.
It can take up to three months for your medication to clearly show up as a new TSH level in your bloodstream. However, in half that time your new free T4 and free T3 levels will have stabilized, and your TSH level may at least have started shifting; so to ensure you aren’t seriously over or under your therapeutic level, your doctor will typically ask you to come back in around six weeks.
Shortly before your second visit, pay attention to your body while skimming through Chapter 2. If you notice any symptoms that you reasonably believe might be caused by either hypothyroidism or hyperthyroidism, jot them down, and be prepared to describe them when your doctor asks how you feel. If your doctor is a good one, she’ll take your symptoms into account along with her physical examination and the results of your second round of blood tests. She’ll then use all this information to fine-tune your dosage.
Thyroidian Tip
It’s common to need a bit less medication but feel as if you need a bit more, and vice versa. But if you changed your dosage on your own, you’d be making a small problem into a bigger one. Instead, simply rely on your feeling that something is wrong, and see your doctor for another round of blood tests. The combination of symptoms, a brief physical exam, and lab results will provide a clear view of the current state of your hypothyroidism.
If the change to your dosage is smaller than what you expected, be aware that these corrections are akin to steering a big ship. If you turn a ship’s wheel too drastically, you’ll soon end up off course. Similarly, when your lab numbers are close to where they should be, doctors prefer gentle and gradual modifications that yield significant results over a month or two.
After your second visit, your doctor will probably ask to see you again in three months, this time allowing for your TSH level to fully reflect your latest dosage change.
If your dosage requires only minor adjustments after your third visit, your doctor will probably ask to see you again in six months or, if your condition appears stable, in a year.
No matter when your next visit is scheduled, you should never hesitate to make an earlier appointment if you notice symptoms returning or getting worse, or new symptoms appearing. Aside from any risks involved, there’s no good reason for you to spend weeks feeling awful when a simple modification of your dosage can restore your good health.
Be Goldilocks
Most doctors beware extremes in either direction, and you should, too—even when they come from your own physician. For example, if a man weighs 180 pounds and his thyroid has shut down, and he’s prescribed 50 mcg of Synthroid, that’s way too low for even a conservative initial dosage. Similarly, if you’re feeling awful for over three months on an exceptionally low dosage and your doctor tells you to be patient, find another doctor.
As another example, if your practitioner tells you to take more than three grains of Nature-Throid—the equivalent of 300 mcg of Synthroid—that’s flat-out dangerous (aside from rare circumstances, such as a patient weighing well over 300 pounds). If you went along, it would plunge you into hyperthyroidism and put you at risk of a heart attack.
Some alternative medicine practitioners rely solely on symptoms and basal temperature (see Chapter 3) and may prescribe daily doses of four grains, five grains, six grains, and more of desiccated thyroid.
Overdosing makes many people feel awful, but some patients become accustomed to the overstimulation. Periodically I’ll see a patient who’s on more than three grains of medication who tells me he feels great. I’ll respond, “You might feel great on cocaine too. That doesn’t mean it’s good for you.” A stimulant is making your body become more active than is normal, and by definition that’s not sustainable. At some point a crash is inevitable.
My first step with such a patient is to taper him off the overdosing as quickly as possible without shocking his system. Sometimes patients come to me too late, however. In as little as six months, serious damage may be done to the heart and bones; plus it’s not unusual for such a patient to enter into a permanent state of hyperthyroidism such as Graves’ disease.
Don’t let this happen to you. Like Goldilocks, steer clear of too little and too much, and stay focused on finding the dosage that’s just right for your body’s needs.
Mixing and Switching Thyroid Medications
As Chapter 8 explained, you have a variety of thyroid medications to choose from and you can mix these thyroid medications however you like to achieve the type of dosage you desire. That’s because your body makes no distinctions between synthetic and natural hormones, or between brand name and generic hormones.
Along the same lines, you can freely switch from one medication to another, as long as you choose the equivalent dosage. If you encounter any transition issues, they’ll typically be because over 99 percent of any thyroid hormone pill consists of inactive filler material, and you may find some fillers make it easier for your body to absorb the active hormones in pills than others (see Chapter 3).
You can see which dosage of thyroid medication is equivalent to the dosage of another medication using the following table.
Thyroid Medication Conversion Guide
Please note the following details about the Conversion Guide:
- Mcg = micrograms; mg = milligrams (1 mg = 1,000 mcg); grain = 65 mg for Nature-Throid/WesThroid, 60 mg for Armour Thyroid.
- Thyrolar = synthetic T4/T3 mix, represented in both mcg and grains (it’s often sold as a desiccated thyroid substitute). For example, 12.5 mcg of T4 and 3.1 mcg of T3 = 1⁄4 grain.
- Nature-Throid and WesThroid are identical medications (see Chapter 3).
- There’s a slight dosage difference between Nature-Throid/WesThroid (1 grain = 65 mg) and Armour Thyroid (1 grain of = 60 mg).>
- All medications are available as pills in the precise dosages listed except for Cytomel (and its generic equivalent liothyronine), which is sold only in 5 mcg, 25 mcg, and 50 mcg dosages. You can create other dosages by cutting and/or combining Cytomel pills.
- T3 is roughly four times as potent as T4—for example, 25 mcg of Cytomel = 100 mcg of Synthroid.
You should be aware that 2 + 2 = 5 when it comes to desiccated thyroid. For example, a 65 mg (1 grain) pill of Nature-Throid contains 38 mcg of T4 and 9 mcg of T3. Given that T3 is about four times as potent as T4, that works out to 74 mcg (38 mcg + 36 mcg) of T4. However, the Conversion Guide shows that a 65 mg pill of Nature-Throid is actually equivalent to a 100 mcg pill of T4. This fact comes from doctors who have decades of experience with patients switching between thyroid medications, and you’ll find the same information in virtually any other conversion guide (for example, see the guide from RLC Labs at Nature-Throid.com/conversionChart.asp).
You might reasonably ask where the extra 26 mcg is coming from. The truth is, no one really knows. However, experts suspect that the T2 and T1 in desiccated thyroid account for its “hidden” extra power.
It’s important to be aware of this discrepancy between desiccated thyroid’s stated active ingredients and its actual potency. If your doctor isn’t experienced with desiccated thyroid, he might look at only the active ingredients and prescribe too much for you. You should therefore always refer to the Conversion Guide when switching between medications … and, if necessary, bring it to your doctor’s attention.
Real Patient Dosage Stories
It can be easier to understand the process of selecting the right dosage within the context of people’s lives. The following are true stories of patients who required medication for their hypothyroidism. They were all restored to full health once they stabilized on the right dosage.
Total Thyroid Hormone Replacement
Dan had a perfectly functioning thyroid. Unfortunately, it developed cancer. To eradicate the disease, it was necessary to surgically remove the thyroid.
I normally ease a patient onto medication gradually. This wasn’t appropriate in Dan’s case, however, because we needed to entirely replace the hormones previously produced by his otherwise healthy thyroid.
Dan weighed 200 pounds, so my initial guess was that he needed the equivalent of 200 mcg of T4 daily. The ways Dan could’ve received this dosage include:
- Synthetic T4: 200 mcg Synthroid pill, or 200 mcg levothyroxine (generic T4) pill.
- Synthetic T4 and T3 mix: 100 mcg Synthroid pill and 25 mcg Cytomel pill; or 100 mcg levothyroxine (generic T4) pill and 25 mcg liothyronine (generic T3) pill; or a 2 grain pill of Thyrolar.
- Natural T4, T3, T2, and T1: Desiccated thyroid via a 130 mg (2 grain) Nature-Throid or WesThroid pill; or a 120 mg (2 grain) Armour Thyroid pill.
Because the only way for Dan to get both a normal amount of T2 and a time-released version of T3 was via desiccated thyroid, I suggested a 130 mg (2 grain) pill of Nature-Throid daily. Dan agreed. Subsequent months of testing—and lack of symptoms—showed that this was just the right medication and dosage for him.
Underdose for Depression
Lori’s problem was depression. She’d tried four major antidepressants, but none of them worked for her. When Lori came to me for help, she mentioned that she’d been taking 75 mcg of Synthroid for the past five years. That’s a small amount for most adults, so I immediately suspected underdosing as the source of Lori’s ills.
Blood tests confirmed this; Lori’s TSH was high and her hormone levels below normal. I raised her prescription to 100 mcg of Synthroid, and asked Lori to come in for another round of testing in three months. I also told her to come in right away if she noticed any signs of hyperthyroidism, such as her heart rate increasing.
Three months later, Lori’s depression had largely lifted. However, she was now complaining of fatigue. When I questioned her, it turned out that once Lori had started feeling better, she’d begun training for a marathon—on top of taking a full load of courses for a Master’s degree! When the lab results came in, they showed Lori’s TSH and thyroid hormone levels were now perfect. I explained to Lori that it was simply her newfound enthusiasm for life that was wearing her out. Once Lori adjusted to being healthy again, she was fine on the 100 mcg dosage.
Overdose for Fatigue
Josie was feeling severely fatigued. She first saw a doctor who followed the principles of Broda Barnes (see Chapter 3). Using only the basal temperature test, he diagnosed her as hypothyroid and prescribed a 120 mg (2 grain) pill of Armour Thyroid. When these had no effect, he progressively raised her dosage, reasoning that her symptoms would be resolved once Josie had enough thyroid hormones.
When Josie was up to 240 mg (4 grains) of Armour Thyroid daily, her heart was pounding in her chest and she was periodically fainting. At that point she came to see me for a second opinion.
I first told Josie that we needed to immediately taper her off the extreme overdose she’d been prescribed. I added that since she was feeling just as much fatigue as before, there was a good chance her problem was never caused by her thyroid at all.
I took Josie’s blood and ordered a series of tests. A few days later the results showed Josie was in the late stages of Addison’s disease (see Chapter 14).
I helped wean Josie completely off her thyroid medication, and placed her on medication that directly addressed her adrenal disease. After six months, Josie was feeling enormously better.
A Dog’s Tale
Margy was doing fine on her thyroid medication, so I was surprised to get a panicked call from her toward the end of a warm summer day. All my nurse told me was there’d been an overdose.
“Hello, Margy,” I said. “Are you okay?”
“I’m fine,” she said. “But I keep my Armour pills by the bed, and my dog knocked the bottle over while I was away at work and ate them all. There was a two-week supply in there! I’m afraid he’s going to die!”
I shook my head. “It’s probably the mild pig smell that attracted him. This happens from time to time.”
“He’s running around chasing his tail! Should I rush him to the emergency room?”
“It would do no harm to have him checked by your vet,” I said, “but he’ll probably be fine. Dogs use a lot more thyroid hormone per pound than people. The most important thing you can do is put the pills where he can’t get at them in the future.”
“Like where?” Margy asked.
“You can store them in the freezer,” I said. “Not only will it prevent your dog from accessing the pills, it’ll end their mild odor, so he won’t even be interested in them when you take them out in the morning. It’s probably the warm summer day—which caused some of the pills’ molecules to drift into the air—that made him go after them in the first place.”
If you have children at home, similar advice applies—always keep your thyroid medication in a safe place where no one can reach them but you. All the reasons for you to avoid an overdose—risk of heart damage, your thyroid shutting down, etc.—go double for young ones.
Staying on Your Medication
After meeting all the challenges involved with hypothyroidism—identifying the disease, getting the right tests done, interpreting the lab results correctly, choosing the appropriate medication, and determining the perfect dosage—you’d think that patients would take their pills without fail every morning.
Oddly enough, though, some don’t. Once their symptoms have gone away, and their pills run out but nothing terrible immediately happens, a certain number of patients fail to renew their medication because they feel like they’ve been “cured.”
In fact, hypothyroidism is usually a long-term disease, and within anywhere from a week to a couple of months of no treatment its symptoms will return. This can happen so slowly and subtly that it’s not immediately obvious. Making matters worse is that one of the symptoms is often a slowing of mental faculties that affects judgment. As a result, someone can be suffering for quite a while before realizing what’s happening.
You should therefore virtually never go off your medication unless your doctor tells you it’s okay to do so. The only exception is if you’re experiencing symptoms of hyperthyroidism; and in this case, you should call your doctor immediately to get advice and make an appointment.
As long as you stay on your medication, pay close attention to your body for hypothyroidism symptoms, and see your doctor for a physical exam and blood tests at least once a year, you should be able to live as rich and healthy a life as anyone with a perfectly functioning thyroid.
The Least You Need to Know
- Your thyroid medication dosage is determined by the degree of your thyroid’s inactivity and your weight.
- Don’t hesitate to mix thyroid medications to achieve the exact type and dosage of medicine you need.
- If your hypothyroidism symptoms return, or you notice new symptoms, see your doctor for a new round of tests.
- Keep taking your thyroid medication first thing every morning unless your doctor tells you otherwise.