Below are a list of drugs and other substances that may reduce blood platelet counts in some individuals.  Reactions vary. 

According to an article by Dr. James George, "Quinidine, quinine, sulfonamides, nonsteroidal anti-inflammatory drugs, and gold compounds were among the most frequently reported drugs..." (that cause thrombocytopenia).See Dr. George's web site for more information on drug-induced thrombocytopenia.

The Blood Center of Southeastern Wisconsin has a laboratory that can test for drug-induced thrombocytopenia and other platelet problems.

(Note: PDSA is in the process of adding references to all of the items on this list. Until that project is complete background information can usually be found by searching the Internet using "substance platelets" or "substance thrombocytopenia" as search criteria)

Drugs that can significantly reduce platelet counts

• [A] Drug Induced Thrombocytopenia
• [E] The Essential Guide to Prescription Drugs, 1997, James J. Rybacki, Pharm.D. and James W. Long, M.D.

Anxiety/Depression

• diazepam [A,E] - antianxiety, tranquilizer (Valium, among others)
• chlorpromazine [A] - antipsychotic, tranquilizer (Chlorpromanyl, Largactil, Thorazine)
• imipramine [E] - antidepressant (Antipress, Apo-imipramine, Impril, Janimine, Tipramine)
• thiothixene [A] (Navane)

Arthritis

• penicillamine [E] - antiarthritic, heavy metal poisoning, (Cuprimine, Depen)

Attention Deficit Disorder

• methylphenidate hydrochloride (Ritalin) thrombocytopenia purpura is listed as a side-effect

Cancer

• levamisole [A,E] (Ergamisol)
• interferon alpha [A] (Roferon A, Intron A)
• tamoxifen [A] (Nolvadex)

Cholesterol

• atorvastatin calcium (lipitor) - binds to plasma proteins See: Atorvastatin-induced severe thrombocytopenia. (Research Letters) Author/s: Maria Luisa Gonzalez-Ponte Issue: Oct 17, 1998 - Lancet

Diabetes

• chlorpropamide [A,E] - antidiabetic, (Apo-Chlorpropamide, Chloronase, Diabinese, Glucamide)

Fungus Infection

• amphotericin B [A] (Amphocin, Fungizone)

Gout

• allopurinol [E] - Used to control gout (Alloprin, Lopurin, Novopurol, Purinol, Zurinol, Zyloprim)

Hair Loss

• minoxidil [A,E] - antihypertensive, hair growth stimulant (Minodyl, Minoximen, Rogaine)

Heartburn

• cimetidine [A,E] - Heartburn Tagamet, also Zantac, Pepcid in same class of Histamine H-2 blocking drugs
• ranitidine [A,E] - H-2 Receptor blocker (Zantac)

Heart Conditions

• acetazolamide [E]- Used for glaucoma, seizures, retention of fluid in congestive heart failure, mountain sickness
• amiodarone [A,E] (Cordarone)
• amrinone [A] (Inocor)
• diltiazem [E] - antianginal, antihypertensive, calcium channel blocker (Apo-Diltiaz, Cardizem)
• digoxin[A,E] - digitalis preparations, congestive heart stimulant and treatment of heart rhythms. (Lanoxicaps, Lanoxin, Novodigoxin.)
• procainamide [A,E] - antiarrhythmic (Apo-Procainamide, Procamide, Procanbid, Promine, Rhythmin)
• quinidine [A,E] - antiarrhythmic (Apo-Quinidine, Cardioquin, Duraquin, Quinora)

High Blood Pressure / water retention

• chlorothiazide [A,E] - diuretic, antihypertensive (Aldoclor, Diachlor, Diupres, Didudrigen, Diuril, Supres
• chlorthalidone [E] - antihypertensive, diuretic (Apo-Chlorthalidone, Combipres, Hygroton-Reserpine, Thalitone, Uridon)
• furosemide [E] - antihypertensive, diuretic (Lasix, Lo-Aqua, Luramide)
• quinapril hydrochloride (Accupril)

Infections

• ampicillin [A,E] - antibiotic used to treat infections (Amcill, Ampicin, Ampilean, Omnipen, Polycillin, Penbritin, Principen)
• cephalosporins[E] - anti-infectives
• cefaclor (Ceclor), cefadroxil (Duricef, Ultracef), cefamandole (Mandol) cefazolin (Ancef, Kefzol, Zolicef) cefixime (Suprax) cefmetazole (Zefazone), cefonicid (Monocid) cefoperazone (Cefobid) ceforanide (Percef) cefotaxime (Claforan), cefotetan (Cefotan) cefoxitin (Mefoxin) cefprozil (Cefzil) ceftazidime (Fortaz, Tazidime, Tazicef) ceftizoxime (Cefizox), ceftriaxone (Rocephin) cefuroxime (Ceftin, Kefurox, Zinacef) cephalexin (Keflex, Keftab) cephalothin (Keflin) cephapirin (Cefadyl) cephradine (Anspor, Velosef) moxalactam (Moxam) Omnicef
• nalidixic acid [A]- (Negram)
• penicillin V [E] - antibiotic causes abnormal bleeding or bruising
• pentamidine isethionate - (Pentam, NebuPent, Pentacarinate)
• rifampin [A,E] - antibiotic (Rifadin, Rifamate, Rofact)
• sulfamethoxazole [A]- anti-infective (Apo-Sulfatrim, Bactrim, Comoxol, Septra, etc.)
• trimethoprim/sulfamethoxazole [A,E] - anti-infective (Apo-sulfatrim, Bactrim, Coptin, Septra)
• vancomycin [A,E] - anti-infective (Vancocin, Vancoled, Vancor)

Inflammation/Pain

• acetaminophen [A] (Tylenol, Panadol, others) - considered safe by many, however, some incidences of platelet reduction were found in journal articles.
• aspirin [E] (acetylsalicylic acid, ASA) relief of mild to moderate pain and inflammation. Causes decreased number of white blood cells and platelets.
• ibuprofen [A] - NSAID
• diclofenac [A,E] - analgesic NSAID, (Apo-Diclo, Arthrotec, Cataflam, Novo-difenac,Voltaren)
• meclofenamate sodium [A] - NSAID (Meclomen)
• morphine [E] - analgesic, opioids
• naproxen - NSAID, (Naprosyn)
• pregabalin (Lyrica) - Source
• piroxicam [E] - NSAID, analgesic, (Apo-Piroxicam, Feldene, Novopirocam, Nu-Pirox)
• sulfasalazine [A,E] - bowel anti-inflammatory (Azaline, Azulfidine, Salazopyrin)

Malaria

• chloroquine [E] - used to treat malaria and amebic infection , causes bone marrow depression (Aralen, Kronofed-A-JR)
• hydroxychloroquine (Plaquenil) - antimalarial, immunosuppressant, used in lupus, rheumatoid arthritis, causes bone marrow suppression

Premenstrual Distress

• Sarafem

Seizure Disorders

• acetazolamide [E] - anticonvulsant (Ak-Zol, Dazamide, Diamox, Storzolamide)
• carbamazepine [A,E]- anticonvulsant , reduced formation of all blood cells (Apo-carbamazepine, Epitol, Mazepine, Tegretol).
• phenytoin [A,E] - anticonvulsant (Dilantin, Ekko JR, Mebroin, Phelantin)
• topiramate - anticonvulsant (Topamax)
• valproic acid - anticonvulsant (Depakote, Epival)
• zonisamide - (Zonegran) also used for migraine and weight loss

Tuberculosis

• isoniazid [A,E] - antituberculosis (Isotamine, Laniazid, Vitamin B-6)
• ethambutol [A]- (Myambutol)

Others substances that can reduce the number of platelets 

• alcohol
• alfalfa sprouts (may harbor salmonella)
• allicin (contained in Kwai, Kyolic and other garlic supplements)
• chlorine
• dong quai (angelica sinensis) According to Dr. Hoang, it should be avoided in ITP and autoimmune diseases because it has an estrogenic effect and will make autoimmune conditions worse. He said there is a rule: herbs which stimulate female hormones are contraindicated for autoimmune diseases and those which enhance male hormones and vitality are indicated for autoimmune disease
• echinacea
• gold and gold salts
• Metabalife contains Ma Huang and other substances that interfere with blood clotting (see list below).  One of our readers reported a decreased platelet count while using.
• niacin (by causing liver problems)
• pesticides
• phenylpropanolamine (found in decongestants and weight loss products - linked to hemorrhagic strokes)  Click for list of products
• quinine (found in tonic water and bitter melon)
• medications that contain salicylates (ex. Pepto-Bismol, Alka Seltzer)
• aminoglutethimide (Cytraden), aminosalicylic acid (Paser), chenodeoxycholic acid, chlorpheniramine, desferrioxamine, diazoxide, diatrizoate meglumine, gentamicin, hydrochlorothiazide,  levamisole, lopanoic acid (Telepaque), meprobamate, methyldopa, mianserin, naphazoline (Privine, Vasocon-A), nitrofurantoin, oxprenolol, oxyphenbutazone, phenylbutazone, sodium aminosalicylate, sulfonamidesthioguanine, valproate

Substances that reduce the ability to clot

• aspirin
• aspartame (can also cause thrombocytopenia)
• beer (especially dark beer)
• blueberries
• chocolate (dark)
• chondroitin sulfate (can act like heparin)
• coffee1
• vitamin E
• feverfew
• heparin (can also cause thrombocytopenia)
• garlic/onions
• gingko biloba (can also reduce the number of platelets)
• ginger
• ginseng
• goldenseal
• green tea
• guarana
• red/purple grape products (grape juice, red wine, raisins)
• pycnogenol
• Omega 3 fatty acids
• SSRI's (Prozac, etc.)
• Quercetin, rutin, and related bioflavonoids
• ticlopidine (ticlid) used to prevent blood clots
• tomatoes
• wood ear mushrooms
  
  
  

1. Br J Nutr. 2008 Dec;100(6):1276-82. Epub 2008 Apr 28. http://www.ncbi.nlm.nih.gov/pubmed/18439332