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

Diltiazem

Diltiazem

Calcium channel blocker (non-DHP, AV-node active)

AdultCCBNon-DHPAFRate controlHTNAngina

Indication

AF rate control β€’ angina β€’ selected HTN

At a glance

INDICATIONS (CORE USE)

AF rate control, angina, and selected HTN pathways.

ADULT DOSE (STANDARD)

Oral chronic and IV monitored-setting regimens are distinct; follow protocolized dosing.

MAX DOSE

Route/protocol-specific.

Route

PO chronic; IV monitored-setting use

PEDIATRIC DOSE

Specialist only.

Do not miss

Must-not-miss safety points

Major warning

- Bradycardia / AV block risk - HFrEF caution where clinically inappropriate

Indications

USE IF: AF rate control, angina, selected HTN contexts. AVOID IF: symptomatic bradycardia, high-grade AV block, or clinically inappropriate HFrEF use.

Primary

  • AF rate control pathways
  • Angina
  • Hypertension (selected contexts)

Secondary

  • IV monitored-setting rate control workflows

Dosing

STANDARD (ADULT PO)

Differentiate oral chronic pathways from IV monitored-setting pathways.

ADULT DOSE

Titrate by HR/BP, symptoms, and protocol context.

PEDIATRIC DOSE

N/A

MAX DOSE

By route and protocol.

Practical Note

Never treat oral and IV workflows as interchangeable dose paths.

Warnings

Clinical warnings

  • Bradycardia/AV-conduction suppression risk is clinically significant.
  • Negative inotropy/conduction slowing warrants caution in HFrEF contexts.
  • Constipation is high-yield with verapamil and should be anticipated.

Contraindications

  • Symptomatic bradycardia
  • High-grade AV block (without pacing)
  • Clinically inappropriate HFrEF context

Drug interactions

  • Beta-blockers or other AV-node blockers: severe bradycardia / AV block / shock risk
  • Digoxin (especially with verapamil): level rise and AV-block/bradycardia risk
  • CYP3A4/P-gp interaction burden can be clinically significant
  • Beta-blockers/AV-node blockers can cause major conduction suppression.

Special populations

Pediatrics

Specialist only.

Pregnancy

Specialist indication/protocol-dependent use.

Lactation

See lactation references and product labeling.

Renal impairment

Monitor hemodynamics and AV-node effects clinically.

Hepatic impairment

Exposure may rise in hepatic impairment; cautious titration advised.

Elderly

Higher bradycardia/hypotension susceptibility.

Administration

If IV is used, continuous monitored setting is mandatory.

Monitoring

  • Monitor: - Monitor HR + BP and symptomatic bradycardia (fatigue, presyncope) - Use stronger caution in HFrEF or baseline conduction disease
  • Recheck: - Reassess ECG/AV-conduction risk when clinically indicated
  • Hold if:
    - HOLD if HR <50 with symptoms, high-grade AV block signs, or marked hypotension

Overdose / toxicity

Clinical Picture

A) Mild β†’ dizziness, fatigue, bradycardia B) Moderate β†’ hypotension + bradycardia/AV delay, conduction symptoms, hyperglycemia trend C) Severe β†’ shock, high-grade AV block, refractory toxicity

Immediate Actions

β€’ Airway + continuous monitoring (ABC, BP, telemetry) β€’ Hypotension β†’ IV fluids first-line β€’ Refractory hypotension β†’ early vasopressors β€’ Severe toxicity β†’ IV calcium + HIET + toxicology/ICU escalation β€’ Stop CCB immediately

Antidote

- No single antidote - CCB toxicity support β†’ IV calcium, vasopressors, HIET (protocol-guided) - Bradycardia / conduction compromise β†’ pacing when clinically indicated - Refractory severe toxicity β†’ ECMO consideration (center-dependent) - IV lipid β†’ selective toxicology-guided use

Decontamination

β€’ Recent oral ingestion β†’ activated charcoal if protected airway and early presentation (toxicology-guided)

Escalation

- Refractory shock / severe conduction toxicity β†’ ICU + toxicology - Persistent instability despite calcium + vasopressors β†’ HIET / pacing / ECMO pathway

Clinical pearls

Common mistakes, resistance logic, and bedside traps

High-Yield Summary

Diltiazem is a conduction-active CCB, not just a vasodilatory BP pill.

Clinical pearls

IV diltiazem logic belongs to monitored settings; keep oral and IV pathways separate.

CCB safety

    Pharmacokinetics

    Formulation and route determine onset/offset and monitoring intensity.

    Mechanism of action

    Non-DHP calcium channel blockade with AV-node/conduction effects.

    Common brand names

    Saudi Arabia

    Tildiem, Cardizem, Diltiazem

    Global

    (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)
    • ACC / AHA HTN/arrhythmia/HF guidance
    • ESC AF and chronic coronary syndrome guidance where relevant
    • FDA / SFDA product labeling

    Do not miss

    • Bradycardia / AV block risk
    • HFrEF caution / avoid when clinically inappropriate
    • Beta-blocker or AV-node blocker combinations can cause severe bradycardia/shock
    • Hypotension risk with conduction suppression