HEMIN
| HEMIN (hee'min) Panhematin Classifications: blood derivative; enzyme inhibitor; Therapeutic: enzyme inhibitor Pregnancy Category: C |
Availability
7 mg/mL injection
Action
Derived from processed red blood cells. Represses synthesis of porphyrin in liver or bone marrow by blocking production of delta-aminolevulinic acid (ALA) synthetase, an essential enzyme in the porphyrin-heme biosynthetic pathway.
Therapeutic Effect
Effective in ameliorating recurrent attacks of acute intermittent porphyria (AIP).
Uses
Recurrent attacks of acute intermittent porphyria (AIP) only after an appropriate period of alternate therapy has been tried (i.e., glucose 400 g/d for 1–2 d).
Contraindications
History of hypersensitivity to hemin; anticoagulation therapy; porphyria cutanea tarda; pregnancy (category C).
Cautious Use
Lactation. Safe use in children <16 y is not established.
Route & Dosage
| Acute Intermittent Porphyria Adult: IV 1–4 mg/kg/d administered over 10–15 min for 3–14 d, do not repeat dose earlier than q12h (max: 6 mg/kg in 24 h) |
Administration
Intravenous
PREPARE: IV Infusion: ??Reconstitute immediately before use by aseptically adding 43 mL sterile water for injection to vial to yield 7 mg/mL.??Shake well for 2–3 min to dissolve all particles.??Discard unused portions. ADMINISTER: IV Infusion: Give a single dose over 10–15 min. |
- Freeze and store lyophilized powder until time of use.
Adverse Effects (≥1%)
Body as a Whole: Phlebitis (when administered into small veins). Hematologic: Decreased Hct, anticoagulant effect (prolonged PT, thromboplastin time, thrombocytopenia, hypofibrinogenemia). Urogenital: Reversible renal shutdown (with excessive doses).Interactions
Drug: Potentiates anticoagulant effects of anticoagulants; barbiturates, estrogens, corticosteroids may antagonize hemin effect.Pharmacokinetics
Duration: Can be detected in plasma up to 5 d. Elimination: Excess amounts eliminated in bile and urine.Nursing Implications
Assessment & Drug Effects
- Monitor IV site for signs and symptoms of thrombophlebitis (see Appendix F).
- Monitor throughout therapy (decrease in these values indicates favorable clinical response): ALA, UPG (uroporphyrinogen), PBG (porphobilinogen or coproporphyrin).
- Monitor clinical effect of drug therapy by checking patient's symptoms and complaints associated with acute porphyria, which may include depression, insomnia, anxiety, disorientation, hallucinations, psychoses; dark urine, nausea, vomiting, abdominal pain, low back and leg pain, pareses (neuropathy), seizures.
- Monitor I&O and promptly report the onset of oliguria or anuria.
Patient & Family Education
- Notify physician of bruising, hematuria, tarry black stools, and nosebleeds.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug