Over-the-Counter (OTC)Drugs
Aka nonprescription drugs

u Drugs with a relatively low risk of adverse reactions/toxicity if used according to directions & high margin of safety

u Generally used to relieve symptoms of conditions that can be self-diagnosed

u Many categories of OTCs, but we’ll stick with the psychoactive ones

Aspirin (acetylsalicylic acid)

u most common "salicylate" analgesic

u 325-650mg (most do not need more)

u 1. analgesic for mild to moderate pain

u 2. anti-pyretic (anti-fever)

u 3. anti-inflammatory

u Also: anticoagulant action (used to prevent heart attack or stroke due to clots); has anti-colon cancer, anti-skin cancer effects

Adverse Effects of Aspirin

u Causes stomach irritation & bleeding

u 2% of population allergic to aspirin

u Anticoagulant effect is undesirable before or after surgery, during pregnancy, if you are already already a “bleeder”or on anticoagulants

u Can delay & prolong labor & increase bleeding

u In those <16 yr with virus, flu or chicken pox, increased risk of Reye's disease (serious liver & neurological disease)

Signs of Taking Too Much Aspirin (“salicylism:

u Tinnitus (ringing in ears)or impaired hearing, nausea & vomiting, thirst, rapid breathing, confusion

u Lethal dose for average adult ~ 20g (60 tablets)

Drug Action of Aspirin

u Decreases production of body chemicals known as the prostaglandins by inhibiting COX enzymes

u Prostaglandins normally sensitize pain receptors, trigger inflammation & fever, are involved in clotting of blood, protect the cells of the stomach, increase uterine contractions in labor.

u Inhibiting the production of prostaglandins can affect all of these functions

Newest Advance

u Enzymes (COX) producing prostaglandins found in diff. forms in diff. parts of body

u Discovery of selective COX2 inhibitors which relieve pain & inflammation with little effect on stomach or platelets:

l Celebrex (celecoxib)

l Vioxx (rofecoxib)

l (These are prescription drugs)

Acetaminophen ("aspirin substitute or non-aspirin pain reliever")

u 325-650mg (same potency as aspirin) Equal analgesic & antipyretic action

u Not anti-inflammatory or anticoagulant

u Less gastric distress & tinnitus, but more damaging to liver with heavy use

u Can be used by those with aspirin allergy.

u No risk of Reye’s syndrome in kids

Ibuprofen( e.g. Motrin, Advil)

u Both OTC (200 mg) & prescription (higher doses); used every 4-6 hr

u More potent than aspirin or acetominophen (take less)

u More effective for certain conditions (inflammation, joint problems, sports injuries, dysmenorrhea, dental pain)

u Weaker anticoagulant effect than aspirin

Naproxen ( OTC Alleve; Naprosyn or Anaprox)

u Very similar to ibuprofen but somewhat different time course (can take twice a day)

u Both naproxen & ibuprofen are similar enough to aspirin that they should not be used by those with aspirin allergy.

u Similar stomach irritation & should be avoided by those with kidney disease.

u 200mg OTC, higher doses prescription

Naproxen’s Timecourse

u Absorbed more slowly (peaks in 2-4 hrs) & stays longer (binds to proteins in the blood).

u If taken regularly blood levels will be maintained taking just 2 doses a day. PDR states that pain relief lasts UP TO 7-8 hrs.

u FDA pushed 12 hr OTC dosing to limit risks (not just because naproxen sometimes has a longer action).

u Naproxen sodium is absorbed faster.

Ketoprofen (e.g. Orudis, Actron)

u Same analgesic/anti-inflammatory family

u More potent, but otherwise not different in its effects/risks

u OTC dosage is 12.5 mg/4-6 hrs whereas prescription dose is 25-50 mg/6-8 hrs

Non-Steroidal Anti-Inflammatory Drugs (NSAIDS)

u All of these except acetominophen relieve inflammation. There are additional prescription NSAIDS that tend to have greater risk of side effects.

u The other group of potent (& hence prescription) anti-inflammatory drugs for are steroids like prednisone

Cold Medications

u Usually contain a “shotgun”* mix of ingredients to relieve symptoms:

l decongestant

l analgesic/antipyretic

l antihistamine

l anti-tussive (anti-cough)

l some include alcohol

l some include stimulants

l Not everyone needs this fixed combination of ingredients!

u More “individualized” preparations now available

Decongestants

u Mild stimulants which constrict blood vessels in nose, sinuses, etc. to reduce stuffiness & runny nose

u Examples:

l phenylephrine

l pseudoephedrine

l phenylpropanolamine*

l oxymetazoline

l xylometazoline

Antihistamines

u Block the action of histamine, the body chemical which triggers allergy-type responses (itchy eyes, sneezing, hives)

u Examples:

l chlorpheniramine

l brompheniramine

l diphenhydramine

l doxylamine

Other Uses

u Antihistamines are also used as

l anti-motion sickness drugs (like Dramamine)

l cough suppressants (like Benedryl Cough Syrup)

l OTC sleep aids (e.g.Bayer PM, Tylenol PM)

u Not really effective for colds

Anti-tussives (cough-suppressants)

u Decrease the cough reflex - good for when you have a tickly, nonproductive cough.

l dextromethorphan

l codeine

l diphenhydramine (antihistamine)

Expectorants

u Loosen/thin phlegm to make it easier to clear lungs with a productive cough

u Example:

l guaifenesin

Doesn’t make sense to combine cough suppressant with an expectorant