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Thrombolytic / STEMI Pregnancy: Avoid — high bleeding risk including uterine haemorrhage. Alteplase preferred for life-threatening indications in pregnancy.

Streptokinase (STEMI Thrombolysis)

Brand names: Streptase

Adult dose

Dose: 1.5 million units in 100 mL normal saline IV over 60 minutes
Route: Intravenous infusion over 60 minutes
Frequency: Single treatment course only
Max: 1.5 million units (single course only — repeat dosing causes anaphylaxis due to antibody formation)
Bacterial protein (Streptococcus). Activates plasminogen to plasmin. Largely superseded by alteplase and tenecteplase in STEMI. Can ONLY be given once — anti-streptokinase antibodies form within 5 days and persist for years. If further thrombolysis needed — use tPA (alteplase/tenecteplase).

Paediatric dose

Route: IV
Seek specialist opinion — rarely used in children. Alteplase preferred.

Dose adjustments

Renal

No dose adjustment required

Hepatic

Use with caution in severe hepatic impairment (coagulopathy)

Clinical pearls

  • Once-only lifetime rule: streptokinase is derived from Streptococcus — it is highly immunogenic. Anti-streptokinase antibodies form within 5 days of administration and persist for years (possibly lifelong). A second course causes anaphylaxis AND is ineffective (antibodies neutralise the drug). Document clearly in patient records — patient must carry warning card.
  • GUSTO-1 comparison: streptokinase was inferior to accelerated alteplase for 30-day mortality in STEMI (7.3% vs 6.3%). Lower intracranial haemorrhage rate with streptokinase but overall outcomes better with tPA. Streptokinase now rarely used in UK where alteplase/tenecteplase available.
  • Hypotension management: streptokinase causes hypotension in ~10% — slow the infusion rate or briefly stop. Unlike true anaphylaxis, this is often mediated by bradykinin release. Pre-treatment with hydrocortisone and antihistamine may be used.
  • Allergy alert card: patients must receive and carry an alert card documenting streptokinase administration date. Any future thrombolytic need must use alteplase or tenecteplase.
  • Historical significance: ISIS-2 trial (1988) — streptokinase + aspirin vs placebo in STEMI established that aspirin + thrombolysis was synergistic and dramatically reduced mortality. Landmark of modern cardiology.

Contraindications

  • Previous streptokinase or anistreplase within 5 days to lifetime (antibody formation — anaphylaxis + treatment failure)
  • Recent streptococcal infection (pre-existing antibodies)
  • Active internal bleeding
  • Recent stroke, surgery, or trauma
  • Severe hypertension
  • Known bleeding diathesis

Side effects

  • Hypotension (common — slow infusion rate, or temporarily stop)
  • Anaphylaxis/allergic reactions (more common than alteplase — bacterial protein)
  • Bleeding (intracranial, major)
  • Fever
  • Reperfusion arrhythmias

Interactions

  • Anticoagulants/antiplatelets — additive bleeding risk

Monitoring

  • Blood pressure continuously during infusion
  • Signs of hypersensitivity/anaphylaxis
  • ECG (reperfusion markers)
  • Neurological status (intracranial haemorrhage)
  • Signs of major bleeding

Reference: BNFc; BNF 90; GUSTO-1 Trial (NEJM 1993); ISIS-2 Trial (Lancet 1988); ESC STEMI 2023; SPC Streptase. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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