Clinical beta

FMBM is currently in clinical beta. Content is for professional review/testing and must not replace local protocols, senior clinical judgment, or official prescribing references.

Drug Monograph

Hydralazine

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USE IF: Adjunct/resistant HTN; selected hypertensive urgency/emergency (IV, protocol); pregnancy-associated hypertension; HFrEF with nitrates when RAAS blockade not tolerated (selected pathways).

AVOID IF: Known hypersensitivity; CAD/ischemic heart disease without plan to control reflex HR and perfusion; precipitous IV dosing without monitoring.

Hydralazine

Direct arterial vasodilator

AdultHTNHFPregnancyCardiologyWardICUEmergency

Indication

Adjunct HTN β€’ Pregnancy HTN β€’ Selected acute IV BP control β€’ HF + nitrate (selected)

At a glance

INDICATIONS (CORE USE)

- Hypertension (adjunct / resistant HTN) - Hypertensive urgency/emergency (IV, selected contexts) - Pregnancy-associated hypertension - HFrEF with nitrates (selected patients when ACEi/ARB not tolerated)

ADULT DOSE (STANDARD)

IV (acute): intermittent IV for BP control β€” protocol-based PO (chronic): start low (e.g. 10–25 mg multiple times daily); titrate cautiously

MAX DOSE

Indication-dependent; chronic high exposure ↑ drug-induced lupus risk

Route

PO / IV

PEDIATRIC DOSE

Specialist / protocol-based only

Do not miss

Must-not-miss safety points

Major warning

- Reflex tachycardia (can worsen ischemia) - Hypotension (especially IV use) - Drug-induced lupus (chronic use) - Not first-line for routine hypertension - Use cautiously in CAD (↑ myocardial oxygen demand)

Indications

Primary

  • Hypertension (adjunct / resistant HTN)
  • Hypertensive urgency/emergency (IV, selected contexts)
  • Pregnancy-associated hypertension

Secondary

  • HFrEF in combination with nitrates when ACEi/ARB not tolerated or in selected populations

Dosing

STANDARD (ADULT PO)

IV: protocol-based intermittent dosing for BP control PO: start low β†’ titrate cautiously; expect frequent daily dosing

ADULT DOSE

IV (acute): intermittent IV dosing for BP control (protocol-based) PO (chronic): start low (e.g. 10–25 mg multiple times daily); titrate cautiously

PEDIATRIC DOSE

Specialist / protocol-based

MAX DOSE

Indication-dependent; dose/duration ↑ drug-induced lupus risk

Practical Note

- Frequent PO dosing often required (short half-life) - Often combined with beta-blocker Β± diuretic to blunt reflex tachycardia and fluid retention - IV: controlled dosing; continuous BP/HR monitoring per protocol

Warnings

Clinical warnings

  • Reflex tachycardia β†’ may worsen angina
  • Hypotension
  • Fluid retention
  • Drug-induced lupus (dose/duration related)
  • Headache, flushing

Contraindications

  • Known hypersensitivity
  • CAD / ischemic heart disease: caution β€” reflex tachycardia ↑ myocardial oxygen demand

Drug interactions

  • Other antihypertensives β†’ additive hypotension
  • Beta-blockers β†’ often required to blunt reflex tachycardia (clinical pairing, not a harmful interaction class)
  • Diuretics β†’ manage fluid retention

Special populations

Pediatrics

Specialist / protocol-based only

Pregnancy

Pregnancy: - Commonly used for hypertension (important indication); coordinate with OB/MFM per protocol Heart failure: - Use with nitrates in selected patients (when ACEi/ARB not tolerated or pathway-specific)

Lactation

Follow current product labeling and specialist guidance

Renal impairment

Parent drug cleared renally in part; titrate to BP/HR; follow labeling in significant renal impairment.

Hepatic impairment

Hepatic metabolism (acetylation); interpatient variability; severe hepatic impairment: cautious titration.

Elderly

Monitor for hypotension and orthostasis; start low.

Administration

- IV: controlled dosing; monitor BP closely - PO: multiple daily dosing (short duration of effect)

Monitoring

  • Monitor: - BP - HR (tachycardia) - Symptoms (headache, flushing)
  • Recheck: - After dose changes - During IV use closely (serial BP/HR per protocol)
  • If inadequate BP control, worsening ischemic symptoms, or intolerable tachycardia at 24–48h on oral therapy β†’ reassess regimen; do not continue blindly without addressing reflex tachycardia and CAD risk
  • Hold if:
    - Symptomatic hypotension
    - Severe tachycardia
    - Suspected lupus syndrome (chronic use)

Overdose / toxicity

Clinical Picture

Hypotension Tachycardia

Immediate Actions

Supportive care Fluid resuscitation if hypovolemic component

Antidote

None specific

Decontamination

Acute ingestion: poison center / supportive pathway per local protocol.

Escalation

Refractory hypotension or ischemia β†’ ICU-level vasopressor and cardiology pathways per protocol.

Clinical pearls

Common mistakes, resistance logic, and bedside traps

High-Yield

  • Rarely used alone β†’ combine with beta-blocker Β± diuretic

Clinical

  • Important option in pregnancy hypertension (when RAAS inhibitors excluded)
  • HF: combine with nitrates for afterload reduction in selected RAAS-intolerant cohorts

Safety

  • Long-term use β†’ think drug-induced lupus

Pharmacy Tool

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Hydralazine 1 mg/mL oral suspension

suspension Β· oral

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Pharmacokinetics

- Hepatic metabolism (acetylation) - Variable half-life (acetylator-dependent)

Mechanism of action

- Direct arteriolar vasodilation

Common brand names

Saudi Arabia

Apresoline, Nepresol

Global

Hydralazine, (placeholder β€” verify local formulation)

Common trade names are curated examples only β€” formulations and availability vary. Verify the exact product name with your local pharmacy and national regulator before prescribing or dispensing.

Country practice notes

Global data (no country-specific data available)

  • Follow local antimicrobial stewardship policy, hospital formulary, and national resistance guidance.
  • Confirm dosing, stock, and restrictions with institutional pharmacy and current product labeling.

References

Saudi Arabia

  • SFDA (Saudi Food & Drug Authority)
  • Saudi National Formulary / MOH (where available)

International

  • WHO Model List of Essential Medicines (verify current edition)
  • US FDA or EU EMA product information (when national SmPC is unavailable)
  • ACOG / obstetric hypertension references (regional)
  • ACC/AHA heart failure guidance (nitrate + hydralazine pathways where applicable)
  • FDA / SFDA product labeling