Houston Methodist. Leading Medicine.
Houston Methodist. Leading Medicine

Risks From Medications

Risks From Medications


Side effects

Some side effects are minor. Others may require your pharmacist or healthcare provider to substitute another medication. To help minimize the side effects:

  • Ask your health-care provider or pharmacist about possible side effects
  • Read the label
  • Report any reactions or allergies to your health-care provider


Unexpected interactions

Many medications can be harmful - even deadly - if taken together. To help prevent interactions:

  • Make a list of medications you take and bring the list to your next appointment
  • Tell you pharmacist or health-care provider about all medications you are taking - including over-the-counter medicines, vitamins and/or dietary supplements ( such as herbal remedies - Gingko, St. John's Wort, etc.)


Drug dependence

Long term use of some medications may lead to physical or psychological dependence. To prevent drug dependence:

  • Ask your health-care provider if any of your medications are habit-forming
  • Ask how much of each medication you can take without becoming addicted

Taking several medications

You may be taking more than one medication. To help avoid problems:

  • Learn about each medication, and know why you are taking it
  • Follow all instructions for using each medication safely
  • Ask your pharmacist if the over-the-counter medications are safe to use with your prescription medications (have an updated list of medications, other over-the-counter medications, vitamins, and any dietary supplements - herbal remedies with you at all times)


Common medications that require blood tests:

Carbamezapine (Tegretol)
Thalidomide (pregnancy test - don't take if pregnant)
Tretinoin (pregnancy test - don't take if pregnant)
Clozapine (Clozaril)
Phenytoin (Dilantin)
Theophylline (Theo-Dur, Theo-24, Uni-Dur)
Procainamide (Procan SR, ProcanBid)
Warfarin (Coumadin)
Lithium (Lithotabs, Lithobid, Eskalith)
Digoxin (Lanoxin)
(Neoral, Sandimmune)
Tacrolimus (Prograf)
Valproic acid (Depakote)