Propranolol Hydrochloride
Propranolol Hydrochloride (中文：普萘洛爾)
Pronunciation
Propranolol hydrochloride 10mg
Common Strengths of Propranolol
Propranolol comes in various dosages, including 10 mg, 40 mg, and 160 mg tablets. It is also available in extended-release capsules and oral solution 5 mg/5 mL [1][3].
Drug Trade Names of Propranolol
The brand names for propranolol include:
- Inderal
- Inderal LA
- Inderal XL [2]
Mechanism of Action
Propranolol is a nonselective beta- blocker. It works by blocking the action of epinephrine (adrenaline) on beta-1 and beta-2 receptors, which reduces heart rate, myocardial contractility, and blood pressure. It also inhibits renin release by the kidneys and diminishes sympathetic nerve outflow from the brain [3].
Route of Administration
- Oral (tablets, extended-release capsules, oral solution)
Dosages
- Hypertension
- Initial dose of 40 mg twice daily, which can be increased to 120-240 mg per day.
- Heart Failure
- Not typically used for heart failure.
- Diabetic Kidney Disease
- Not specifically indicated for diabetic kidney disease.
- Anxiety
- 10 mg tablets can be used to relieve physical symptoms of anxiety, with dosages up to 40 mg before an event[1][3].
Side Effects
| Frequency | Adverse reactions |
|---|---|
| Common (≥1/100 to <1/10) | Problems sleeping |
| Nightmares | |
| Cold hands and feet | |
| Tiredness | |
| Dizziness[1] | |
| Uncommon (≥1/1,000 to <1/100) | Hypoglycaemia (low blood sugar) |
| Bronchospasm [1][3] | |
| Rare (≥1/10,000 to <1/1,000) | Hallucinations |
| Psychosis | |
| Paresthesia of hands | |
| Thrombocytopenic purpura [3] | |
| Very Rare (<1/10,000) | Agranulocytosis |
| Stevens-Johnson Syndrome | |
| Toxic epidermal necrolysis | |
| Systemic lupus erythematosus (SLE) [3] |
Pharmacokinetics
Propranolol is well absorbed from the gastrointestinal tract, with peak plasma levels reached in 2-4 hours. It is extensively metabolized in the liver and excreted in the urine. The elimination half-life is approximately 6-7 hours[3].
Drug Management
Safety
- Propranolol has a boxed warning about not stopping it abruptly, as it may worsen angina or cause a heart attack. Tapering off under medical supervision is required.[1]
- Contraindicated in patients with asthma, certain heart conditions (e.g., heart block, bradycardia), and severe peripheral arterial disorders.
- Caution is advised in patients with diabetes and thyroid disorders[3].
Pregnancy
Propranolol can cross the placenta and may cause fetal bradycardia. It should only be used if the potential benefit justifies the risk to the fetus[3].
Breast Feeding
Propranolol is present in breast milk at low levels. Caution is advised when administering to breastfeeding mothers[3].
Children and Elderly
- Safety and efficacy in children have not been established.
- Elderly patients may require lower doses due to age-related decreases in renal function[3].
Renal Impairment
Dose adjustment may be necessary in patients with severe renal impairment[3].
Monitoring Requirements
Monitor heart rate, blood pressure, and renal function regularly[3].
Drug Interactions
Propranolol interacts with various drugs metabolized by the cytochrome P-450 system. It can increase blood levels and toxicity when co-administered with inhibitors of CYP2D6, CYP1A2, and CYP2C19. It can also interact with antiarrhythmics, calcium channel blockers, and NSAIDs[3].
FAQs
How should I take the tablet?
Take propranolol orally with or without food. Extended-release capsules should not be crushed or chewed[1][3].
What should I avoid while taking?
Avoid alcohol, as it can increase the blood pressure-lowering effects of propranolol. Also, avoid operating heavy machinery if you experience dizziness or fatigue[1][3].
What happens if I miss a dose?
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and resume your regular schedule. Do not double the dose to make up for a missed one[1][3].
Reference
[1] https://www.theindependentpharmacy.co.uk/anxiety/guides/propranolol-guide
[2] https://www.drugs.com/ingredient/propranolol.html
[3] https://www.drugs.com/pro/propranolol.html
[4] https://www.gosh.nhs.uk/conditions-and-treatments/medicines-information/propranolol/
[5] https://go.drugbank.com/drugs/DB00571
