HORMONE REPLACEMENT THERAPY

Q. I am interested in purchasing a natural Hormone Replacement Therapy (HRT). I have an "under-active thyroid" and am currently taking medication (Synthroid) for this condition. I have heard that soy may interfere with thyroid functioning and the supplement I am looking at contains a soy derivative. My doctor does not believe in herbal medicine which is why I am asking you if there are any possible interactions between my current medication and HRT supplements.

A. This is a such an important question! As the world of natural medicine gains recognition, there are more and more questions about which herbs are safe to take with which medications and the variability depending on the specific drug and herb or supplement combination is endless. It's hard to know where to start.

Many believe that because plants or herbs are natural, there are no safety issues with taking as much as you want, when you want. Unfortunately this could not be further from the truth. Most pharmaceutical medications are based on an action of a particular botanical or specific constituent of a botanical substance. That being said, these herbal remedies can be just as effective as some drugs and equally as dangerous.

To answer your question specifically, soy has been shown to suppress thyroid function, and may exacerbate symptoms in individuals already dealing with poor thyroid function, as well as alter the effects of thyroid medication. The good news is that not all natural HRT supplements contain soy. It may be best to look for an alternative product that contains such herbs as Cimicifuga racemosa (Black cohosh), Vitex agnus castus (Chasteberry), Gingko biloba, Angelica Sinensis (Dong Quai), or Glycerrhiza glabra, all of which have been proven effective in alleviating symptoms of menopause, and all soy free. A combination that includes a few of these herbs will not have any adverse effects on thyroid function or interfere with your thyroid medication.

I will also take this opportunity to clear up some confusion with some of the more well known drug and herb/supplement/food interactions.

Combining Medication with Herbs and Supplements
As a general rule, one should never take an herbal remedy that has the same action as the medications they are also currently taking. This may seem counter intuitive, as you would think that it would only helping the medication to do its job better. The truth is that many drugs (as well as botanical supplements) have a very narrow therapeutic index, meaning there is a very small safe dosage range and outside of that range, overdose and toxicity are common. In the case of hypoglycemic medication or anticoagulant medication, both very commonly prescribed, if you take a botanical such as gymnema or nattokinase you may be putting yourself at risk of hypoglycemia or bleeding disorders. Talk to your MD or Naturopath if you are considering taking supplements that may mimic the effects of your current medications. They may choose to lower your medications to counteract the additive effects that your new supplement regime will have. It may seem like common sense to most, but it must also be said that taking any supplement with known effects that would counteract your current medication is also very dangerous.

With Food or Without
This varies from drug to drug, even within the same class of drugs. Many medications can be irritating to the stomach lining or cause stomach upset, others are more readily absorbed when taken with foods. NSAID's, corticosteroids and beta blockers are all examples of medications that should be taken with food to decrease the chance of stomach upset. On the opposite end of the spectrum medications such as penicillin or acetaminophen are better taken away from food. Sometimes the type of food you are eating with your medications matters. There are certain medications that are better absorbed with high fat or lower fat meals and others that cannot be absorbed if paired with certain foods. See some examples throughout this article and always ask your healthcare professional about the specific medications you are taking.

Fibre
Fibre decreases transit time, and as such, if taken with or near medications as well as most supplements, it can interfere or prevent proper absorption. Fibre supplements should always be taken with water and should always be taken away from other supplements and medications.

Grapefruit Juice
There are a great number of medications that use the liver for metabolism, commonly through a pathway using p450 3A4 enzymes. Grapefruit juice also uses this system and if taken with other medications that do, it can plug up the system and prevent the medication from being metabolized and absorbed properly. The drugs are then left in your system longer and can have adverse effects.

Tyramine
MAO Inhibitors and foods rich in tyramine can be a deadly combination, leading to hypertensive crisis. Foods high in tyramine include aged cheeses, ripe avocados, figs, grapes, plums, eggplant, oranges, pineapple, prunes, raisins, all soy products, all processed foods and mature liver and meat. These foods should be avoided while taking MAO inhibitors.

Alcohol
Most medications need to be taken away from alcohol or may even require that alcohol be avoided altogether while taking them. Individuals on anxiolytics such as benzodiazepines, sedatives and many anti-histamines/allergy medication should avoid alcohol, as it can cause further sedation, making everyday activities such as driving a hazard.

St. John's Wort
Digoxin, warfarin, all pharmaceutical Anti depressants, theophylline, cyclosporine, estrogen and some chemotherapeutic drugs all interact in one way or another with St. John's Wort. St John's Wort has similar properties as MAO inhibitors, as such, individuals taking St John's Wort may also want to be careful when eating foods high/rich in tyramine (see above).

Here are some classes of drugs and their more commonly known interactions:

CNS Medications
Antidepressants (Tricyclic Antidepressants, SSRIs, MOA Inhibitors, Lithium)
Be very cautious when taking with St. John's Wort with any pharmaceutical antidepressant, as it may increase serotonin to levels causing serotonin storm/syndrome, which can be very dangerous. 5-HTP also crosses the blood barrier to increase levels of serotonin. Be cautious when taking 5-HTP at the same time as SSRI's, MAO inhibitors as well as some migraine and insomnia medications. Be cautious with the use of SAMe for the same reasons.

Respiratory
Asthma medication
Avoid caffeine while taking asthma medications, such as Theophylline or Pseudoephedrine. Caffeine can increase anxiety and nervousness, as well as increase toxicity of these medications. Cayenne can increase the absorption of theophylline, as well. Avoid using the spice when taking this medication.

Cardiovascular
Anti-coagulants (Warfarin, Heparin, Coumadin)
Individuals taking anticoagulant medications need to be very cautious when taking any supplement that also has blood thinning properties. Here are just a few; Garlic, Ginger, Angelica sinensis (Dong quai), Borage oil, Capsella bursa, Capsicum frutescens, Feverfew, Fish oil, Grape seed, Horse chestnut, Ligustum porteri, Gingko biloba, Nattokinase, St. John's wort, vitamin E, and large doses of vitamin C, to name just a few. Talk to your MD or Naturopath before beginning any of these supplements if already taking an anticoagulant medication, such as warfarin.

It is also important to note that vitamin K is primarily responsible for a large part of the clotting cascade. Eating a diet rich in vitamin K (green leafy vegetables like spinach, kale, broccoli, collard greens and mustard greens) will inhibit the effects of many anti-coagulant medications. If you commonly eat these foods or would like to introduce more of these foods into your diet, speak with your doctor, as you may need to have your medication adjusted.

Calcium Channel Blockers (Amlodipine)
Diets high in sodium or calcium, or individuals taking a calcium supplement, while also taking a Calcium Channel Blocker for high blood pressure may counteract the effectiveness of their medication.

Diuretics
Diuretics increase the amount of calcium in the blood, supplementing with calcium when taking a diuretic could put you into a state hypercalcemia, meaning blood calcium levels are too high. Symptoms of hypercalcemia include nausea, lack of appetite, weight loss, fatigue and confusion. If you are taking a potassium sparing diuretic, such as spironolactone, make sure to limit your intake of potassium rich foods to avoid a dangerous hyperkalemic (high blood potassium levels) state.

Immune
Tetracycline (antibiotic)
Calcium reduces the absorption of antibiotics such as tetracycline. Make sure to wait 2-3 hours after taking your antibiotic to take your calcium supplement or eating foods rich in dairy (No milk). Tetracycline also impairs the absorption of vitamin C. Make sure to take your vitamin C supplement away from your antibiotics. Avoid using Hydrastis canadensis (Goldenseal) or Berberis (Barberry) while taking tetracycline.

Erythromycin
Red wine and Fruit juices can impair the absorption of this type of antibiotic. It is best to take it with only water to ensure it is being effectively absorbed.

Echinacea
There have been reports of exacerbation of autoimmune diseases while taking Echinacea. If you have Rheumatoid arthritis, SLE (Lupus), or other autoimmune disease, be cautious when using supplements that are designed to strengthen your immune system.

Endocrine
Thyroid medication/Synthroid
Individuals who have poorly functioning thyroid glands need to avoid raw foods containing goitrogens, such as broccoli, cauliflower, brussel sprouts, cabbage, collard greens and kale. Once these foods are cooked, their goitrogen content is significantly lessened and are more safe to consume. Individuals with hypothyroidism may also want to avoid soy containing foods as well as supplements, as research is now showing that soy may suppress thyroid function. Particularly women, who are more likely to develop hypothyroidism and may also be seeking natural products to help them through menopause, need to be careful when taking a supplement that contains soy isoflavones while on synthroid. Calcium also interferes with the absorption of most thyroid medications and should not be taken at the same time.

*This is by no means an exhaustive list. It is always recommended before going on any new supplement or supplement regime that you check with your healthcare practitioner to ensure there are no harmful interactions, especially for individuals on a variety of medications.

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