Caffeine: Uses, Mechanism, Dosage, Side Effects & Brands

Explore a complete guide to the drug Caffeine—its introduction, mechanism of action, pharmacokinetics, indications, contraindications, side effects, drug interactions, dosage, brand names, and pricing. Ideal for medical students and professionals.

Table of Contents:

1. Introduction  

2. Mechanism of Action  

3. Pharmacokinetics and Dynamics  

4. Indications  

5. Drug of Choice  

6. Contraindications  

7. Side Effects  

8. Drug Interactions  

9. Dosage  

10. Brand Names & Price  

11. Conclusion

1. Introduction:

Caffeine is a *central nervous system (CNS) stimulant* commonly found in coffee, tea, soft drinks, and energy products. In clinical medicine, *Caffeine Citrate* is used primarily for treating *apnea of prematurity* in neonates and as a stimulant in certain fatigue-related disorders.

2. Mechanism of Action:

Caffeine acts as a *non-selective adenosine receptor antagonist*, which increases neuronal activity and the release of neurotransmitters such as dopamine and norepinephrine. It also *inhibits phosphodiesterase*, increasing cyclic AMP levels, promoting alertness and bronchodilation.

3. Pharmacokinetics and Dynamics:

- *Absorption:* Rapid oral absorption

- *Peak plasma concentration:* 30–60 minutes

- *Half-life:* Adults: 3–7 hours; neonates: up to 100 hours

- *Metabolism:* Liver (CYP1A2)

- *Excretion:* Renal

4. Indications:

- *Apnea of prematurity*

- *Migraine and tension headaches (adjunct)*

- *Fatigue and drowsiness*

- *Post-dural puncture headache*

- *Enhancing alertness and physical performance*

5. Drug of Choice:

- *Apnea of prematurity* – Caffeine citrate is preferred over theophylline due to fewer side effects and simpler dosing.

6. Contraindications:

- Hypersensitivity to caffeine

- Uncontrolled hypertension

- Cardiac arrhythmias

- Severe anxiety disorders

- Peptic ulcer disease (use with caution)

7. Side Effects:

- *Mild:* 

Restlessness, insomnia, tremors, increased urination

- *Moderate:* 

Palpitations, gastrointestinal upset

- *Severe:* 

Arrhythmias, seizures (in high doses), dependency

8. Drug Interactions:

- *Increased effects:* with other stimulants (e.g., ephedrine)

- *Reduced clearance:* with ciprofloxacin, oral contraceptives

- *Reduced effect of:* sedatives like benzodiazepines

- May interact with *CNS-active agents* and increase their side effects

9. Dosage:

- *Apnea of prematurity (Caffeine Citrate):*

  - Loading dose: 20 mg/kg IV/PO

  - Maintenance: 5–10 mg/kg/day

- *Adults (oral tablets):*

  - 100–200 mg every 3–4 hours as needed (max 400 mg/day)

10. Brand Names & Price:

Caffeine Citrate:

  - Brand: Cafcit®️ (USA)  

  - Form: Injection/Oral solution  

  - Price: ~15–50 per vial  

Caffeine Tablets:

  - Brands: NoDoz®️, Vivarin®️, Alert®️  

  - Price: 5–10 per pack of 100 mg tablets

11. Conclusion:

Caffeine is not just a common beverage ingredient but also a *clinically significant drug*. It plays a vital role in neonatal care and fatigue management. While generally safe, its *use must be cautious* in sensitive populations due to potential side effects and drug interactions.