OTC Drug Chart & CYP2D6 Interactions PDF

Drug/Route Classification Indication MOA Adverse rxn/side effects Drug interactions Blackbox APAP Management of mild to moderate pain. Reduction of fever. Metabolized by CYP450 and is detoxified by glutathione (Phase II conjugation) Adults: N/V, headache, insomnia Peds: N/V, constipation,...

Drug/Route Classification Indication MOA Adverse rxn/side effects Drug interactions Blackbox APAP Management of mild to moderate pain. Reduction of fever. Metabolized by CYP450 and is detoxified by glutathione (Phase II conjugation) Adults: N/V, headache, insomnia Peds: N/V, constipation, pruritus, agitation Acetylcysteine is the antidote Hepatotoxicity: associated with acute liver failure, sometime resulting in liver failure or death. Injury occurs when exceeding the recommended max daily limit. NSAIDs GI ulcers, perforation, bleeding. Increased risk of MI, HF, HTN, stroke. Na+ and H2O retention causing edema. Methotrexate -- decreased methotrexate clearance. P2Y12 inhibitors and SSRIs -- increased risk of bleeding. Bisphosphonates -- increased risk of GI bleeding and ulcers Digoxin -- decreased renal clearance (monitor) Phenytoin + ibuprofen -- displacement of protein binding sites (monitor) ASA Inhibit prostaglandin synthesis from arachidonic acid by inhibiting both isoforms of the COX enzyme (Cox-1 and Cox-2) Contraindicated: pt with vit K deficiency, hx of bleeding disorder. Contraindicated: in peds who have influenza or chicken pox due to risk of Reye's syndrome Similar to NSAIDs Valproic acid -- displacement of valproic acid from protein binding sites and inhibition of valproic acid metabolism Sulfonylureas: increased risk of hypoglycemia Pseudoephedrine AKA Sudafed D Decongestant direct binding and displacement of norepinephrine from storage vesicles and pre junctional nerve terminals limit use for patients with hypertension Linezolid, MOAIs, and ergot derivatives: increased risk of HTN SNRIs- increased risk of tachycardia Diphenhydramine (Benadryl) Chlorphenamine Doxylamine (Unisom) 1st gen antihistamine More sedating 🡪 - Anticholinergic - Antiserotonin - Anti-alpha-adrenergic effects compete with histamine at central and peripheral histamine type 1 receptor sites preventing the histamine receptor interaction and subsequent mediator release Dryness of the eyes and mucous membranes (mouth, nose, vagina), blurred vision, urinary hesitancy and retention, constipation, and reflex tachycardia Contraindicated in newborns or premature infants, lactating women, and patients with narrow angle glaucoma Potassium chloride- increased risk of ulcers Loratadine (Claritin) Cetirizine (Zyrtec) Levocetirizine (Xyzal) Fexofenadine (Allegra) 2^nd^ gen antihistamines Zyrtec is the most sedating second-generation antihistamine inhibit the release of mast cell mediators and may decrease cellular recruitment Budesonide (Rhinocort) Fluticasone (Flonase) Triamcinolone (Nasacort) intranasal corticosteroids inhibit multiple cell types and mediators, including histamine, and affectively stop the "allergic cascade" Epistaxis Long term use has been linked to changes in vision, glaucoma, cataract formation, increased risk of fungal infections, and growth inhibition in children avoid co-use with protease inhibitors: may lead to Cushing\'s syndrome Cromolyn sodium Mast cell stabilizer Must be used one week prior to exposure of allergens Blocks the influx of calcium into mast cells, thereby preventing degranulation and leukotriene release Codeine (Cheratussin AC) PRODRUG Antitussives Acts centrally on the medulla to increase the cough threshold CYP2D6 polymorphisms lead to unpredictable clinical response and potential toxicity in affected persons. Poor metabolizers may not benefit from codeine. Extensive metabolizers are at an increased risk for sedation and respiratory depression CYP2D6 inhibitors bupropion, fluoxetine + paroxetine = reduces the effect of codeine because codeine is a prodrug risk of serious, life threatening, or fatal respiratory depression and the risk of opioid addiction, abuse, and misuse Dextromethorphan (Robitussin or Delsym) NOT A PRODRUG Antitussives Noncompetitively antagonizes N-methyl-D-aspartate (NMDA) and glutamate-induced excitation of excitotoxicity in the CNS and spinal regions No analgesic or additive properties because it is a D-isomer of the codeine analog of levorphanol CYP2D6 inhibitors bupropion, fluoxetine, + paroxetine = may decrease dextromethorphan metabolism, increasing the psychoactive effects of dextromethorphan SSRIs + MAOIs = may increase the risk of serotonergic (psychoactive) effects of dextromethorphan Abused for its phencyclidine-like euphoric effect (robo-tripping) Guaifenesin (Mucinex) Mucinex D (guaifenesin + pseudoephedrine) Mucinex DM (guaifenesin + dextromethorphan) Expectorants Loosens and thins lower respiratory tract secretions, making minimally productive coughs more productive Large doses, either alone or in combination with ephedrine or pseudoephedrine, have been associated with development of renal calculi Antacids ONSET: 5 minutes Buffering agent Magnesium- diarrhea Aluminum- constipation Calcium- renal calculi possible if preexisting renal impairment Sodium bicarbonate- alkalosis possible if preexisting renal impairment BLUF: minimal concerns unless there is severe renal decompensation Doxycycline, ciprofloxacin, levofloxacin, etc = chelation via divalent bonds (Ca2+ or Mg2+) Cimetidine (Tagamet) Famotidine (Pepcid) Histamine Type 2 (H2) ONSET: 30-45 minutes inhibiting histamine on the H2 receptor of the parietal cells (site of HCl production) Cimetidine- antiandrogenic effect (decreased libido, impotence, or gynecomastia in men) Cimetidine- inhibits CYP450, 1A2, and 2C19 = the bid one is opioids Omeprazole (Prilosec) Esomeprazole (Nexium) Lansoprazole (Prevacid) Pantoprazole (protonix)- RX only Proton Pump Inhibitors (PPI) ONSET: 60 minutes C. Diff infxn Long term use- inscreased risk for osteoporosis related fx of hip, wrist, or spine Omeprazole- inhibits CYP2C19 = citalopram, clopidogrel, warfarin, tacrolimus, mycophenolate, etc. \^\^\^ \*\*FOR antacid drug: increasing the pH of the stomach will cause lots of drug interactions. For example: azoles, protease inhibitors, fluoroquinolones, thyroxine, digoxin, and others Pyrantel pamoate (Pin-X) treats Pinworms OTC labeled for two years and up weight based dosing starting at 11 mg/kg, not to exceed 1 gram pyrantel base Depolarizing neuromuscular agent that stimulates the release of acetylcholine and inhibits cholinesterase, thereby paralyzing adult worms in the GI tract. Paralyzed adult worms lose their hold on the intestinal wall and are eventually passed out in the stool Codeine and dextromethorphan. Discuss the drug interaction between the 2. One is a prodrug, one is now---which one? Important to understand prodrugs and efficacy vs. toxic amounts. Know CYP2D6 interaction with both drugs. - - - - - - - - - - - - - - Max amount for PO (tablet or capsule) of acetaminophen, ibuprofen, and naproxen for adults and pediatrics (not naproxen for pediatrics.) - - - - - - - - - - - - OTC drugs for pregnancy and lactation - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Extra: +-----------------------+-----------------------+-----------------------+ | Dz | Drugs | MOA | +=======================+=======================+=======================+ | Vulvovaginal | Azoles (clotrimazole, | inhibit CYP 450 | | Candidiasis | miconazole, | enzymes in the cell | | | tioconazole) | membrane of the | | | | infecting pathogen. | | | Topical (monistat) | Decreases synthesis | | | 1-7 days of therapy. | of the fungal sterol | | | 7 days if pregnant | ergosterol | +-----------------------+-----------------------+-----------------------+ | vaginal itching and | hydrocortisone 1% or | | | irritation | benzocaine 5 to 10% | | +-----------------------+-----------------------+-----------------------+ | overactive bladder | oxybutynin patches | anti muscarinic | +-----------------------+-----------------------+-----------------------+ - Menthol 2-16% and Camphor 3.2%: provides cooling sensation - Capsaicin 0.1-0.15%: provides warm sensation - Causes of non-allergic rhinitis - - Antihistamine / mast cell stabilizer products - - - - Dermatologic disorders: - - - - - - - - Vitamins: +-----------------------------------+-----------------------------------+ | Vitamin | Interaction | +===================================+===================================+ | Vitamin B12 (cyanocobalamin) | Macrocytic anemia | +-----------------------------------+-----------------------------------+ | Vitamin B9 (folic acid) | reduction of neural tube defects | +-----------------------------------+-----------------------------------+ | Calcium and Vitamin D | osteoporosis | +-----------------------------------+-----------------------------------+ | Iron | microcytic anemia | +-----------------------------------+-----------------------------------+ | Vitamin E | used topically for scar | | | minimization | +-----------------------------------+-----------------------------------+ | Coenzyme Q10 | (HEART) | | | | | | reduction of statin associated | | | adverse effects | +-----------------------------------+-----------------------------------+ | Fish oil | (HEART) | | | | | | hypertriglyceridemia | +-----------------------------------+-----------------------------------+ | Red yeast rice | (HEART) | | | | | | Hypercholesterolemia | +-----------------------------------+-----------------------------------+ | Vitamin B3 (Niacin) | | +-----------------------------------+-----------------------------------+ | Melatonin | (BRAIN) | | | | | | insomnia and jetlag | +-----------------------------------+-----------------------------------+ | Valerian Root | (BRAIN) | | | | | | insomnia and anxiety | +-----------------------------------+-----------------------------------+ | St. Johns wort | (BRAIN) | | | | | | depression, anxiety and OCD | +-----------------------------------+-----------------------------------+ | Kava | (DRUG OF ABUSE) | | | | | | severe liver damage | +-----------------------------------+-----------------------------------+ | Echinacea, Sambucus nigra | (TISSUE) | | (elderberry), vitamin C (ascorbic | | | acid), zinc | prevent and treat colds- may | | | decrease duration of infection by | | | one to two days | +-----------------------------------+-----------------------------------+ | Probiotics | (TOILET) | | | | | | GI flora restorations | | | | | | Refrigerated products are | | | preferred by gastroenterologist | +-----------------------------------+-----------------------------------+ | Saw Palmetto | (GU) | | | | | | Just males -- BPH | +-----------------------------------+-----------------------------------+ | Black cohosh | (GU) | | | | | | Just females \-- premenstrual | | | syndrome, dysmenorrhea, and | | | menopause | +-----------------------------------+-----------------------------------+ | Evening primrose oil | (GU) | | | | | | Just females \-- PMS and | | | menopause | +-----------------------------------+-----------------------------------+ | \*\* drug interactions are most | | | likely to occur with | | | antidepressants and blood | | | thinners | | +-----------------------------------+-----------------------------------+