ADHD Overview - Brain Buzz 101
- A neurodevelopmental disorder characterized by persistent, impairing patterns of inattention and/or hyperactivity-impulsivity.
- Key neurobiology: Dysregulation of Dopamine (DA) and Norepinephrine (NE) pathways, especially within the Prefrontal Cortex (PFC), crucial for executive function.
- Diagnostic pointers (DSM-5): Symptoms must appear before age 12 and manifest in at least two distinct settings.

⭐ Core symptoms of ADHD include a persistent pattern of Inattention, Hyperactivity, and Impulsivity that interferes with functioning or development.
Stimulants - The Focus Fuelers
| Feature | Methylphenidate (MPH) | Amphetamine (AMP) |
|---|---|---|
| MOA | Blocks DAT & NET; ↑ DA & NE in cleft | Blocks DAT & NET; ↑ DA & NE release; reverses transporter |
| Onset | IR: 20-60m; ER: 60-90m | IR: 20-60m; ER: 60-90m |
| Duration | IR: 3-5h; ER: 8-12h | IR: 4-6h; ER: 10-12h |
| Brands | Inspiral, Concerta, Ritalin | Adderall, Vyvanse (prodrug) |
| Key Diff. | Milder S/E, ↓ abuse risk | More potent, ↑ euphoria & abuse risk |
- Insomnia, anorexia (↓ appetite, weight loss), headache, irritability, abdominal pain.
- 📌 Mnemonic: Stimulants SPEED you up (insomnia, irritability) but slow your GROWTH (appetite/weight loss in children).
- Less common: Tics, psychosis, ↑ BP & HR.
⭐ Cardiovascular monitoring (BP, HR) is crucial before and during stimulant therapy. Baseline ECG if cardiac history is present or suspected.
Non-Stimulants - The Steady Sidekicks
Alternative if stimulants unsuitable. Slower onset, smoother, sustained effect.
| Drug | MOA | Onset | Specific Indications | Key Adverse Effects (AEs) |
|---|---|---|---|---|
| Atomoxetine | NRI (Selective NE Reuptake Inhibitor) | 2-4 wks (full 6-8) | ADHD ± tics/anxiety. 📌 'A' for 'Alternative'. | GI upset, insomnia, ↑HR/BP; BBW: Suicidal ideation; hepatotoxicity (rare). |
| Clonidine ER | Alpha-2 Agonist | 1-2 wks | ADHD + impulsivity, aggression, tics, sleep; adjunctive. | Sedation, hypotension, bradycardia. ⚠️ Abrupt stop: rebound HTN. |
| Guanfacine ER | Selective Alpha-2A Agonist | 1-2 wks | ADHD + impulsivity, hyperactivity; adjunctive. More selective α2A. | Sedation (less vs Clonidine), hypotension, bradycardia. ⚠️ Abrupt stop. |
⭐ Atomoxetine: preferred for ADHD with substance abuse risk or tics.
Treatment Tactics - ADHD Rx Roadmap
- Initiation & Titration:
- Stimulants (Methylphenidate/Amphetamine) first-line (age ≥6).
- Titrate stimulants q 1-2 weeks ("Start low, go slow"); monitor response/SEs.
- Non-stimulants (Atomoxetine, Viloxazine, Alpha-2 agonists) slower titration (Atomoxetine 2-4 weeks).
- Trials & Switching:
- Adequate trial: 4-6 weeks optimal dose before switching.
- Stimulant failure/SEs → switch stimulant class.
- Both fail → try non-stimulants (Atomoxetine/Viloxazine). Alpha-2 agonists (Clonidine/Guanfacine ER) monotherapy/adjunct.
- Monitoring:
- Baseline & regular: Height, weight (growth charts), HR, BP.
- SEs: Insomnia, ↓appetite, mood changes, tics.
- Stimulant Holidays:
- Planned breaks (weekends/summers) assess need.
- ↓SEs (growth; 📌 "Stimulant Vacation" for catch-up), ↓tolerance.
⭐ Regular monitoring for efficacy, side effects (especially cardiovascular and growth parameters), and the potential for misuse or diversion is essential for all ADHD medications.
High‑Yield Points - ⚡ Biggest Takeaways
- Stimulants (Methylphenidate, Amphetamines) are first-line ADHD treatment, blocking dopamine (DAT) and norepinephrine (NET) reuptake.
- Key stimulant side effects: insomnia, anorexia, weight loss, headache, abdominal pain.
- Atomoxetine, a non-stimulant SNRI, is an alternative with slower onset of action.
- Alpha-2 agonists (Clonidine, Guanfacine) are used as adjuncts or monotherapy.
- Crucial monitoring for stimulants includes growth, BP, HR, sleep, and appetite.
- Drug holidays may be advised for stimulants to mitigate adverse effects_._
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