Explore the comprehensive medical guide on Amphetamine: its mechanism of action, pharmacokinetics, therapeutic uses, dosage, side effects, contraindications, brand names, price, and antidote. Essential for healthcare professionals and students.
Table of Contents:
1. Introduction
2. Mechanism of Action
3. Pharmacokinetics & Pharmacodynamics
4. Indications
5. Drug of Choice
6. Contraindications
7. Side Effects
8. Dosage
9. Brand Names & Price
10. Antidote
11. Conclusion
1. Introduction:
Amphetamine is a *central nervous system stimulant* used to treat *ADHD*, *narcolepsy*, and occasionally *obesity*. It enhances alertness, attention, and energy by increasing specific neurotransmitter levels in the brain. It is a *Schedule II controlled substance* due to its high abuse potential.
2. Mechanism of Action:
Amphetamine increases the release of *dopamine* and *norepinephrine* in the brain and inhibits their reuptake. This leads to increased synaptic concentrations, resulting in enhanced focus and alertness.
3. Pharmacokinetics & Pharmacodynamics:
- *Absorption:* Rapid oral absorption
- *Onset:* 30–60 minutes
- *Half-life:* 9–14 hours
- *Metabolism:* Hepatic (CYP2D6 pathway)
- *Excretion:* Primarily in urine (pH-dependent)
4. Indications:
- Attention-Deficit/Hyperactivity Disorder (ADHD)
- Narcolepsy
- Obesity (short-term, off-label)
5. Drug of Choice:
Amphetamine is a *first-line drug* for *ADHD* in children and adults due to its efficacy in improving attention span, behavior, and cognitive function.
6. Contraindications:
- Glaucoma
- Use of MAO inhibitors within 14 days
7. Side Effects:
Common:
- Insomnia
Serious:
- Growth suppression in children
8. Dosage:
ADHD:
- Children: Start at 2.5–5 mg/day, increase as needed
- Adults: 5–30 mg/day in divided doses
Narcolepsy:
- 5–60 mg/day in divided doses
Note: Dosage should be individualized.
9. Brand Names & Price:
Brand Names:
- Adderall®️
- Dexedrine®️
- Evekeo®️
- Vyvanse®️ (prodrug: lisdexamfetamine)
Price (US):
- Generic: 20–50/month
- Branded:100–200/month
(Prices vary by region and availability)
10. Antidote:
There is *no specific antidote* for amphetamine overdose. *Supportive care* is the mainstay:
- *Activated charcoal* (if early)
- *Benzodiazepines* for agitation/seizures
- *Cooling* for hyperthermia
- *Antihypertensives* if needed
- Acidifying urine (e.g., ammonium chloride) may enhance excretion
11. Conclusion:
Amphetamine remains a cornerstone in ADHD and narcolepsy management due to its proven benefits. However, due to its *abuse potential* and possible side effects, medical supervision is essential. Understanding its pharmacology, proper dosing, and safety profile ensures its effective and responsible use.
