What is the starting dose of a medication?

Starting Dose Recommendations

The starting dose depends entirely on which medication you are prescribing, as there is no universal starting dose applicable to all drugs. Below are evidence-based starting doses for commonly prescribed medications organized by therapeutic category.

Cardiovascular Medications

Antihypertensives

• Lisinopril: Start with 10 mg once daily in adults with hypertension 1

  • Reduce to 5 mg once daily if patient is already taking diuretics 1
  • For patients with creatinine clearance 10-30 mL/min, start with 5 mg once daily 1
  • For hemodialysis patients or creatinine clearance <10 mL/min, start with 2.5 mg once daily 1

• Propranolol (for infantile hemangiomas): Start with 1 mg/kg/day divided into three doses in infants >4 weeks old without comorbidities 2

  • For preterm infants or those with comorbidities, start with 0.5 mg/kg/day 2
  • Increase to 2 mg/kg/day after 24 hours if tolerated 2

Heart Failure

• Enalapril: Start with 2.5 mg twice daily 2
• Bisoprolol: Start with 1.25 mg once daily 2
• Carvedilol: Start with 3.125 mg twice daily 2
• Spironolactone: Start with 25 mg once daily 2
• Eplerenone: Start with 25 mg once daily 2

Neurological Medications

Migraine Treatment

• Sumatriptan:

  • Subcutaneous: 6 mg, may repeat in 1 hour (max 12 mg/24h) 2
  • Oral: 25-100 mg every 2 hours (max 200 mg/day) 2
  • Intranasal: 5-10 mg in one nostril, may repeat after 2 hours (max 40 mg/day) 2

• Rizatriptan: Start with 5-20 mg orally every 2 hours (max 30 mg/day) 2

• Naratriptan: Start with 1.0-2.5 mg orally every 4 hours (max 5 mg/day) 2

Migraine Prophylaxis

• Flunarizina: Start with 5-10 mg once daily at bedtime 3
  • In elderly patients, start with 5 mg/day due to increased risk of extrapyramidal symptoms 3

Epilepsy/Bipolar Disorder

• Lamotrigine: Start with 25 mg once daily for the first two weeks, then titrate gradually 4
  • Critical: Never exceed recommended dose escalation rates to minimize serious rash risk 4

Psychiatric Medications

Alzheimer's Disease Management

Antipsychotics (Atypical - First Line):

• Risperidone: Start with 0.25-0.5 mg/day (max 2 mg/day) 2
• Olanzapine: Start with 2.5 mg/day at bedtime (max 10 mg/day) 2
• Quetiapine: Start with 12.5 mg twice daily (max 200 mg twice daily) 2

Mood Stabilizers:

• Trazodone: Start with 25 mg/day (max 200-400 mg/day in divided doses) 2
• Carbamazepine: Start with 100 mg twice daily, titrate to therapeutic level 2
• Divalproex sodium: Start with 125 mg twice daily, titrate to therapeutic level 2

Anxiolytics:

• Buspirone: Start with 5 mg twice daily (max 20 mg three times daily) 2

Antidepressants:

• Desipramine: Start with 10-25 mg in the morning (max 150 mg/day) 2
• Nortriptyline: Start with 10 mg at bedtime (max 40 mg/day) 2

Rheumatologic Medications

Gout Management

• Allopurinol: Start with ≤100 mg/day (lower in CKD stage ≥3), then titrate up 2

  • Consider starting with ≤50 mg/day in patients with CKD 2
  • Maximum FDA-approved dose is 800 mg/day 2

• Febuxostat: Start with ≤40 mg/day, then titrate 2

• Probenecid: Start with 500 mg once to twice daily, then titrate 2

Gastrointestinal Medications

Chronic Constipation

• Polyethylene glycol (PEG): Titrate based on symptom response (specific starting dose not provided in guidelines) 5
• Magnesium oxide: 400-500 mg daily 5
• Bisacodyl: 5 mg daily for short-term or rescue use 5

Dermatologic Medications

Bullous Pemphigoid

• Prednisolone: Start with 0.75 mg/kg/day or less (approximately 30-52.5 mg/day for a 70 kg patient) 2
  • Doses >0.75 mg/kg/day do not confer additional benefit and increase mortality 2
  • Some recommend lower starting doses of 20-40 mg/day 2

Critical Withdrawal of Life Support

Symptom Management

• Morphine (opioid-naïve patients): Start with 2 mg IV bolus, titrate to effect 2

  • Bolus doses should be available every 15 minutes as needed 2

• Midazolam (benzodiazepine-naïve patients): Start with 2 mg IV bolus followed by 1 mg/h infusion 2

  • Bolus doses should be available every 5 minutes as needed 2

Key Principles for All Starting Doses

• Start low, go slow: Lower starting doses reduce the risk of adverse effects and allow for safer titration 2
• Adjust for renal/hepatic impairment: Many medications require dose reduction in organ dysfunction 1
• Consider patient age: Elderly patients often require lower starting doses due to altered pharmacokinetics and increased sensitivity 3
• Monitor response: Therapeutic drug monitoring may be necessary for medications with narrow therapeutic windows 6
• Titrate to effect: Most medications require gradual dose escalation to achieve therapeutic benefit while minimizing adverse effects 2, 7