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Combined analgesic + sympathomimetic Pregnancy: There is no evidence of the product's safety in human pregnancy nor evidence from animal work that it is free from hazard. Avoid in pregnancy and lactation. Midrid should not be taken during the post-partum period.

Paracetamol with isometheptene

Brand names: Midrid (discontinued)

Used in: Burns

A combination preparation for acute migraine pairing the analgesic paracetamol with isometheptene, a sympathomimetic agent with vasoconstrictor activity.

Adult dose

Dose: Treatment of migraine and other vascular headaches. Midrid 325 mg/65 mg capsules (each capsule contains paracetamol 325.0 mg and isometheptene mucate 65.0 mg): adults 2 capsules at once, then 1 capsule every hour until relief is obtained, up to a maximum of 5 capsules within a 12 hour period.
Route: Oral
Frequency: 2 capsules at once, then 1 capsule every hour until relief is obtained
Max: 5 capsules within a 12 hour period
SCOPE - PINNED PRODUCT ONLY: MIDRID 325MG/65MG CAPSULES (MHRA PL001110205, DHP Healthcare Limited). Other paracetamol/isometheptene products would differ and are not covered. The SPC's only indication is migraine and other vascular headaches (no separate tension-headache regimen is given). Do not exceed the recommended dose; if symptoms persist consult a doctor. Women should not take Midrid during the post-partum period: there have been several reports of life-threatening cerebral vasoconstriction or intracranial haemorrhage after therapeutic doses of isometheptene in the first few weeks after childbirth. Do not take with any other paracetamol-containing products. Seek immediate medical advice in the event of an overdose, even if feeling well, because of the risk of delayed serious liver damage. Children: not recommended, so no paediatric figure is given.

Dose adjustments

Renal

Severe renal impairment is a contraindication; care is advised in the administration of this product to patients with renal impairment. No dose-adjustment figure is given. Cases of high anion gap metabolic acidosis due to pyroglutamic acidosis have been reported with paracetamol in patients with severe illness such as severe renal impairment and sepsis.

Hepatic

Severe hepatic impairment is a contraindication; care is advised in the administration of this product to patients with hepatic impairment. No dose-adjustment figure is given. The hazards of paracetamol overdose are greater in those with non-cirrhotic alcoholic liver disease.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via MHRA Products — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Severe cardiac, hepatic or renal impairment
  • Severe hypertension
  • Glaucoma
  • Patients on monoamine oxidase inhibitor therapy
  • Porphyria
  • Hypersensitivity to paracetamol and/or other constituents

Side effects

  • Transient dizziness may appear in hypersensitive patients; this can usually be eliminated by reducing the dose
  • Circulatory disturbances may occur
  • Hypersensitivity reactions including skin rashes, anaphylaxis, angioedema and urticaria; very rare cases of fixed drug eruption
  • Blood dyscrasias including thrombocytopenic purpura and agranulocytosis have been reported (not necessarily causally related to paracetamol); blood disorders have also been reported with isometheptene-containing products
  • High anion gap metabolic acidosis due to pyroglutamic acidosis (frequency not known) in patients with risk factors using paracetamol
  • Isometheptene, like other sympathomimetics, may cause autonomic dysreflexia in patients with high spinal cord lesions
  • Post-partum: life-threatening cerebral vasoconstriction or intracranial haemorrhage reported after isometheptene in the first few weeks after childbirth

Interactions

  • Monoamine oxidase inhibitors: contraindicated; increased risk of a hypertensive crisis when sympathomimetics are given with MAOIs
  • Bromocriptine and isometheptene: increased risk of toxicity
  • Cardiac glycosides, quinidine, anti-hypertensives and tricyclic anti-depressants: care should be taken on theoretical grounds
  • Alcohol reduces the liver's capacity to deal with paracetamol
  • Colestyramine reduces absorption of paracetamol; metoclopramide and domperidone accelerate absorption of paracetamol
  • Flucloxacillin: high anion gap metabolic acidosis due to pyroglutamic acidosis, especially in patients with risk factors
  • Chloramphenicol: may interact, causing increased plasma levels
  • Warfarin and other coumarins: anticoagulant effect may be enhanced by prolonged regular use of paracetamol, with increased risk of bleeding; occasional doses have no significant effect

Monitoring

  • Caution in cardiovascular disease, diabetes mellitus and hyperthyroidism
  • Care in patients with renal or hepatic impairment, and in non-cirrhotic alcoholic liver disease
  • If high anion gap metabolic acidosis due to pyroglutamic acidosis is suspected, discontinue paracetamol promptly and monitor closely; measuring urinary 5-oxoproline may help identify it
  • Post-partum women should not take this product

Clinical monograph

How it works

Paracetamol provides central analgesia and antipyresis, while isometheptene is an indirectly acting sympathomimetic thought to relieve migraine through cranial vasoconstriction.

Prescribing in practice

  • Because isometheptene is a sympathomimetic vasoconstrictor, it should be avoided in uncontrolled hypertension, significant cardiovascular or cerebrovascular disease and with monoamine oxidase inhibitors.
  • Account for paracetamol from all sources to prevent inadvertent overdose and liver injury.
  • Restrict the frequency of use to avoid medication-overuse headache and excessive sympathomimetic exposure.

Monitoring

Monitor blood pressure in those with cardiovascular risk and review headache frequency to detect medication-overuse headache.

Counselling the patient

  • Do not take other paracetamol-containing products alongside this medicine.
  • Limit how often you use it for migraine attacks, and seek advice if headaches become more frequent or your blood pressure is a concern.

Evidence & guidelines

Paracetamol with a sympathomimetic for migraine is used according to its SPC, with cardiovascular cautions reflecting the vasoconstrictor component.

Reference: Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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