Medication Interactions and Side Effects

Medications are intended to make you feel better, but to a patient experiencing an adverse drug reaction, nothing could feel further from the truth. By learning the ins and outs of PH medications, it’s possible to avoid common interactions and anticipate common side effects. Read on for information from PH-treating medical professionals to help you ensure that your medications are doing what the doctor ordered…helping you to live your life.

PH Medication Interactions

Each of the drug classes used to treat pulmonary hypertension have several side effects and drug interactions. Here, medical professionals share some of the most common problems encountered by PH patients. Please note that the list below is not comprehensive. Talk to your PH doctor before starting any new medications.

  • Endothelin receptor antagonists have been associated with birth defects and liver damage. Your doctor may request monthly liver function tests (LFTs) to prevent irreversible liver damage. Patients on Tracleer must have monthly LFTs. Although LFT monitoring is no longer mandatory for patients on Letairis, PHA’s Scientific Leadership Council issued a consensus statement in March 2011 advising PH-treating physicians to test liver function at the outset of all treatments for pulmonary hypertension and, at the prescriber’s discretion, at periodic intervals thereafter.
  • PDE-5 inhibitors should not be taken in combinations with nitrates, nitric oxide donors or alpha blockers, as taking these drugs in combination may cause a significant drop in blood pressure, which could result in loss of consciousness or even death. You should make certain that you are not taking these medications before starting either Revatio or Adcirca.
  • Prostacyclins tell your blood vessels to dilate, and they can become dangerous when combined with other medications that do the same thing. There are precautions your physicians need to consider when combining prostacyclins with diuretics (water pills), antihypertensives (for high blood pressure) or any other vasodilators (hydralazine, nitrates, sildenafil), as these combinations may actually lower your blood pressure too much.
  • Warfarin (Coumadin) is designed to minimize blood clot formation in the pulmonary blood vessels, a benefit that can be dangerously enhanced by the addition of a long list of medications and supplements, including some antibiotics; over-the-counter medications like Tylenol, Motrin, Advil, Naprosyn and Aleve; vitamins; herbal supplements; and some foods. Call your doctor if you miss any doses or notice any unusual bruising or signs of bleeding. Have your INR (International Normalized Ratio) checked regularly to assess bleeding and clotting tendencies.

Birth Control and Hormonal Therapy

There is debate among PH-treating medical professionals about the use of hormonal therapy in women with PH. The information here is adapted from a consensus statement issued by PHA’s Scientific Leadership Council. Be sure to discuss this important issue with your PH team, as the specifics of your situation may influence the options available to you.

  • Birth control: PH specialists recommend that sexually active women with PH use at least two and preferably three forms of birth control, as pregnancy poses dangerous risks to both mother and child. Doctors do not encourage hormonal contraceptives, including the birth control pill and the birth control patch, because they can increase your risk of blood clots. Certain PH medications may also decrease their effectiveness. Instead, talk to your doctor about barrier methods (condoms and diaphragms with spermicide), estrogen-free products, and surgical options (tubal ligation for women, or a vasectomy for your male partner if you’re in a monogamous relationship).
  • Post-menopause: In a survey of 23 PH-treating physicians in North America and Europe, 65% indicated that use of hormonal therapy in post-menopausal women with PH was acceptable.

Over-the-Counter Medications and Supplements

While they don’t require a prescription, over-the-counter (OTC) medications and herbal supplements may be harmful, and should be used cautiously if you have PH. Certain ingredients in these drugs may have a direct effect on the heart and lungs or may interact with medications commonly prescribed for PH. As with prescription drugs, talk to your PH doctor before taking anything new. Here are a few important interactions you should know about.

  • Avoid decongestants and medications that contain stimulants (including cold, flu, sinus, allergy, and headache medications). These medications cause vasoconstriction (narrowing of blood vessels), and may worsen PH and increase blood pressure and heart rate. They may also cause palpitations and irregular heart rhythms. Medications that contain antihistamines (e.g., diphenhydramine, Benadryl, Claritin) may be used to treat cold symptoms, allergies, and hay fever, provided that they do not also contain decongestants.
  • Aspirin, Advil, Motrin, Naprosyn, Aleve and Tylenol should be used with caution in patients taking warfarin (Coumadin). Talk to your PH specialist before taking Non-Steroidal Anti Inflammatory (NSAID) medications such as Advil, Motrin, Naprosyn and Aleve. NSAIDs may cause swelling and fluid retention. – see above.
  • Herbal therapies should be viewed as drugs, not simply as “natural supplements.” Discuss these drugs with your PH specialist prior to taking anything new. PHA’s Scientific Leadership Council has issued a consensus statement on some of the commonly used agents that may lead to complications when taken in combination with select PH medications, including ephedra (ma huang), dong quai, St. John’s Wort, ginseng, ginkgo, danshen, papaya extract, kava, Echinacea, valerian, vitamins A, E, and K and others.
  • Any ingredient contraindicated in patients with high blood pressure is, as a general rule, contraindicated in patients with PH. If you’re uncertain about the contents of a specific medication, ask a pharmacist for assistance.

Treatment Side Effects

Even the world’s leading PH doctors can’t list all of the potential side effects for PH-treating medications, because every PH patient is different. A few of the most common side effects are listed below. Visit the Treatments page to learn more.

  • Endothelin receptor antagonists (ERAs): Common side effects include headache, nausea, nasal congestion, low blood pressure, liver test abnormalities, decreased sperm counts, swelling/edema, decreased appetite and a metallic taste in the mouth.
  • PDE-5 inhibitors: Common side effects include headache, low blood pressure, increased likelihood of erection in men, visual disturbances and increased indigestion.
  • Prostacyclins: The most common side effects include headache, nausea, diarrhea, flushing, low blood pressure, jaw pain, low platelets and rash. There are also side effects associated with the route of administration. Patients on intravenous prostacyclins may experience line infections, blood clots or skin reactions to the tape used to secure their line. Patients on subcutaneous prostacyclins may experience site pain, redness or infections. Patients on inhalation therapy may experience a sore throat, cough or chest pain.

What You Can Do to Protect Yourself

  • Inform prescribers of every medication and supplement you’re taking. Keep a list of current medications with you at all times so no important information slips through the cracks.
  • Read the package insert and any patient education materials about your treatments. Pay special attention to the sections on side effects, toxic effects and drug-to-drug interactions.
  • Talk to your pharmacist about any interactions that may occur.
  • Contact your PH specialist prior to starting a new medication prescribed by another of your physicians to make sure it will not interact with your PH medications or worsen your condition.
  • Only take medications as they are prescribed.
  • It’s generally not a good idea to “make up” for a missed dose of PH medications.

Medical review by Traci Stewart, RN, MSN, CHFN, Cardiomyopathy Treatment Program, University of Iowa.

To review Conflict of Interest Disclosures for PHA’s medical leadership, visit: Disclosures
Last reviewed: February 2012