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Haemodialysis Pregnancy: Avoid — animal studies show fetal risk; limited human data

Midodrine (Intradialytic Hypotension)

Brand names: Bramox, Gutron

Adult dose

Dose: 2.5-10 mg given 30-60 minutes before haemodialysis session
Route: Oral
Frequency: Before each haemodialysis session (not more than 3 times daily)
Max: 10 mg per dose; 30 mg/day
Alpha-1 adrenergic agonist prodrug — converted to desglymidodrine. Used to prevent symptomatic intradialytic hypotension. Do NOT take in the evening (supine hypertension risk — 4-hour action). Check supine BP before each dose.

Paediatric dose

Route: Oral
Seek specialist opinion — not licensed in children for this indication

Dose adjustments

Renal

Metabolite accumulates in renal failure — use lowest effective dose (2.5 mg) and monitor supine BP closely. The dialysis session itself removes some midodrine.

Hepatic

Caution in hepatic impairment — reduced prodrug conversion

Clinical pearls

  • Intradialytic hypotension (IDH) definition: systolic BP fall >20 mmHg during dialysis — occurs in 20-30% of haemodialysis sessions and is associated with accelerated cardiac, renal, and cerebral ischaemia. Midodrine effectively prevents IDH by maintaining peripheral vascular resistance during fluid removal.
  • Key safety rule: NEVER take midodrine within 4 hours of bedtime — supine hypertension can cause hypertensive stroke. Some centres recommend patients sleep with the head of bed elevated 20-30 degrees.
  • Non-pharmacological approaches to IDH should always be tried first: reduce dry weight target, cool dialysate (35-36 degrees C), isolated ultrafiltration, sodium profiling, reduce interdialytic weight gain
  • Midodrine is also used in hepatorenal syndrome (HRS) — typically combined with terlipressin or octreotide + albumin infusion. Separate indication from dialysis-associated IDH.
  • Dose timing: give 30-60 min pre-dialysis to allow absorption and onset; the peak effect coincides with the maximum fluid removal period.

Contraindications

  • Severe organic heart disease
  • Acute renal retention
  • Phaeochromocytoma
  • Thyrotoxicosis
  • Supine hypertension (BP >180/110 mmHg supine)
  • Hypersensitivity

Side effects

  • Supine hypertension (CRITICAL — take last dose of day no later than 6 pm)
  • Piloerection/goosebumps (predictable alpha effect)
  • Tingling/itching scalp
  • Urinary retention (alpha-1 stimulation)
  • Bradycardia (reflex)

Interactions

  • Alpha-blockers (doxazosin, tamsulosin) — pharmacological antagonism; avoid combination
  • Digoxin — additive bradycardia
  • Fludrocortisone — additive pressor effect (sometimes used intentionally in autonomic failure)
  • MAOIs — hypertensive crisis risk; contraindicated

Monitoring

  • Supine and erect BP (before each dose)
  • Intradialytic BP (continuous during session)
  • Urinary symptoms (retention)
  • Piloerection/side effects

Reference: BNFc; BNF 90; Perez-Garcia et al. (Intradialytic Hypotension); KDOQI Haemodialysis Adequacy Guidelines; SPC Bramox/Gutron. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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