Paracetamol orodispersible or rectal
| Paracetamol orodispersible or rectal | |
| What is it? | Non-opioid analgesic |
| Mechanism of action | Weak COX2 and peroxidase inhibitor |
| Starting dose | 500 mg–1000 mg, maximum four times a day |
| Time to onset of effect | Uncertain (15–30 min with oral route)17 |
| Formulation | Paracetamol FasTab 250 mg oradispersible tablets (2–4 tablets per dose, dependent on weight and liver function) Paracetamol suppositories 1 g; n.b. bioavailability is 60% compared with oral administration3 |
| Indication | Pain, fever |
| Common adverse effects | Rectal ‘anorectal erythema’ with rectal preparation16 |
| Contraindications | Severe liver dysfunction, 500 mg four times a day maximum if weight less than 50 kg |
| Caution | Old age, poor nutritional state, fasting, anorexia, weight <50 kg, chronic alcohol use17 |
| Licencing | Both are licensed formulation |
| Benefits | Transmucosal alternatives for managing fever |
| Risks | Ensuring correct number of orodispersible are used; ensuring that dose is reduced to 500 mg four times a day if weight less than 50 kg or liver function tests severely deranged |
| Cost | £4.12 for 24×250 mg orodispersible tablets (Fastmelts—would need four tablets per 1 g dose); £59.50 for 10×1 g suppositories |