M6: Over the Counter Drugs

Question 1

What are Over the Counter (OTC) Drugs?

Answer 1

Definition:
Medications available without a prescription at drugstores or supermarkets (aka non-prescription drugs)

General Characteristics:
1. Safe when used at recommended doses

2. Limited toxicity with self-limiting symptoms (however, overdoses are harmful & could be fatal)
3. Effective but less potent than prescription alike medications

Question 2

Common Indicators of OTC Drugs

Answer 2

1. ANALGESICS/ANTIPYRETICS
   Indications = pain, headache, other aches
2. COLD PREPARATIONS
   Indications = common cold, sore throat
3. ANTITUSSIVES, EXPECTORANTS, MUCOLYTICS
   Indications = cough
4. ANTIHISTAMINES (local steroids and antifungals)
   Indications = allergies, itching, skin rash
5. ANTACIDS, ANTIDIARRHEALS, LAXATIVES
   Indications = Gi upset
6. VITAMINS, MINERALS, AMINO ACIDS
   Indications = supplements
7. SUNSCREEN, ACNE PREPARATIONS
   Indications = skin protection

Question 3

Safe Use of OTC Drugs

Answer 3

1. Mild illness
2. Familiar with symptoms and the drug
3. Read the label carefully and follow directions
4. Keep a current list of taken medicines
5. Consult with physician or pharmacist if:
   - unfamiliar with the drug or symptoms
   - symptoms get worse
   - develop adverse effects (stop drug)
   - pregnant or breastfeeding (before taking the drug)
6. Don’t:
   - Combine medicines with the same active ingredients
   - Use for more than 2 weeks

Question 4

How to Select OTC Drugs

Answer 4

Select the drug that has:
1. Proven efficacy

2. Simplest formulation
3. A list of all ingredients with their concentrations
4. Proper dose
5. Appropriate administration form – e.g., liquid for children
6. Known level of toxicity

Question 5

Examples of Analgesics/ Antipyretics

Answer 5

1. Acetaminophen (Tylenol®)
2. NSAIDs:
   - Acetylsalicylic acid (ASA) (Aspirin®)
   - Ibuprofen (Advil®)
   - Naproxen (Aleve®)

Question 6

(4) COLD PREPARATIONS
- Mechanism of Action
- Adverse Effects
- Preparations
- Administration

Answer 6

1. ANTIHISTAMINES

DRUGS:
1. Older drugs:
- Chlorphenamine (= Chlorpheniramine)
- Diphenhydramine (Benadryl®)

2. More recent drugs:
   - Loratadine (Claritin®)
   - Cetirizine (Zyrtec®)

MECHANISM:
Block histamine (H1) receptors.

ADVERSE EFFECTS:
1. Anticholinergic symptoms
2. Drowsiness (more with older drugs)

PREPARATIONS:
1. Alone
2. Combined with other medications

ADMINERESTRATIONS:
1. Oral: tablets – syrup
2. Topical: skin cream – nasal spray – eye drops
3. Injections

2. DECONGESTANTS

DRUGS:
1. Pseudoephedrine (oral)
2. Phenylephrine – Oxymetazoline (local)

MECHANISM:
1. Alpha1 (1) agonists:
Vasoconstriction of blood vessels of nasal mucosa
2. Doses are too low to be very effective

ADVERSE EFFECTS:
1. May increase blood pressure in hypertensive patients
2. May lead to rebound congestion after stopped
3. Use in children under 6 is not approved

3. ANTITUSSIVES

DRUGS:
1. Dextromethorphan (Benylin®)
2. Codeine

MECHANISM
1. Suppress the cough center in the medulla

INDICATIONS:
1. Dry (non-productive) cough (cough suppressants)

ADVERSE EFFECTS:
1. Risk of dependence (more with codeine)

4. EXPECTORANTS

DRUG: Guaifenesin (= Glyceryl guaiacolate) (Mucinex®)

MECHANISM:
1. Increase volume & reduce viscosity of bronchial secretions
2. Allow cilia to expel loosened secretions

INDICATIONS:
Productive cough (with viscid mucus secretions)

ADVERSE EFFECTS:
Renal stones

Question 7

Drug Interactions with OTC Drugs

Answer 7

1. Antihistamines + CNS depressants &/or alcohol
   - Increase CNS depression
2. Decongestants + MAOIs
   - Malignant hypertension and IHD
3. ASA + Anticoagulants
   - Increase risk of bleeding
4. Aluminum Antacids
   - Decreases absorption of some drugs
5. Mineral Oil Laxative
   - Decreases absorption of some drugs