Promethazine 10 mg: Uses, Dosage, Side Effects & Precautions Explained

What is Promethazine 10 mg ?

Promethazine 10 mg is a prescription antihistamine used to treat allergies, nausea, motion sickness, and as a sedative. It works by blocking histamine H1 receptors and affecting certain areas of the brain that control nausea and vomiting.

🧬 How Promethazine Works:

Promethazine blocks histamine receptors in the brain and other parts of the body. It also has antiemetic (anti-nausea) and sedative effects due to its influence on the central nervous system (CNS). This makes it useful for a variety of conditions.

📋 Indications / Uses:

Promethazine 10 mg is commonly used for:

• Allergy symptoms (runny nose, itching, hives, rash)
• Motion sickness
• Nausea and vomiting
• Sedation (pre- or post-operative)
• Sleep aid (short-term use)
• Adjunct to pain relief medications
• Prevention of nausea during anesthesia or chemotherapy

💡 Dosage & Administration:

Always follow your doctor’s instructions. Do not self-medicate.

📌 Typical Adult Dosage:

• Allergies: 25 mg at bedtime or 12.5 mg twice daily
• Motion sickness: 25 mg taken 30–60 minutes before travel; repeat every 8–12 hours if needed
• Nausea/Vomiting: 12.5–25 mg every 4–6 hours as needed
• Sedation: 25–50 mg at bedtime
• Pre-surgery: 50 mg night before and/or 25–50 mg on the day of surgery

📌 Pediatric Dosage:

• Varies by age and weight. Use only under pediatric supervision.
• Not recommended for children under 2 years due to risk of fatal respiratory depression.

⚠️ Warnings & Precautions:

• Do not use in children under 2 years of age
• May cause severe drowsiness or respiratory depression
• Caution in patients with:
  • Asthma or COPD
  • Glaucoma
  • Liver disease
  • Seizure disorders
• Avoid alcohol and other CNS depressants
• Can impair mental and physical ability (e.g., driving)

🔄 Drug Interactions:

Promethazine may interact with:

• CNS depressants (e.g., benzodiazepines, opioids, alcohol)
• MAO inhibitors (e.g., selegiline, phenelzine)
• Anticholinergic drugs (e.g., atropine)
• Antipsychotics – increased risk of side effects like tremors or dizziness
• Certain antidepressants – additive drowsiness

🚫 Contraindications:

• Children under 2 years
• Hypersensitivity to promethazine or other phenothiazines
• Comatose patients
• Severe CNS depression

⚠️ Side Effects:

✅ Common:

• Drowsiness or sedation
• Dry mouth
• Dizziness
• Blurred vision
• Constipation

❗ Serious (Seek Immediate Medical Help):

• Breathing difficulty
• Confusion or hallucinations
• Seizures
• Severe allergic reactions (rash, swelling)
• Jaundice (yellowing of skin/eyes)

🤰 Use in Pregnancy & Breastfeeding:

• Pregnancy: Generally considered safe (Category C), but should be used only if clearly needed.
• Breastfeeding: May pass into breast milk; consult with your healthcare provider.

📦 Storage:

• Store at room temperature (20–25°C / 68–77°F)
• Protect from moisture and light
• Keep out of reach of children