Classifications: blood derivative; enzyme inhibitor; Therapeutic: enzyme inhibitor
Pregnancy Category: C
7 mg/mL injection
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.
Effective in ameliorating recurrent attacks of acute intermittent porphyria (AIP).
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 12 d).
History of hypersensitivity to hemin; anticoagulation therapy; porphyria cutanea tarda; pregnancy (category C).
Lactation. Safe use in children <16 y is not established.
Route & Dosage
|Acute Intermittent Porphyria
Adult: IV 14 mg/kg/d administered over 1015 min for 314 d, do not repeat dose earlier than q12h (max: 6 mg/kg in
- Administer via a large arm vein or central venous catheter to reduce risk of phlebitis. Terminal filtration through a sterile
0.45 micron or smaller filter is recommended.
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 23 min to dissolve all particles.??Discard unused portions.
ADMINISTER: IV Infusion: Give a single dose over 1015 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).
Potentiates anticoagulant effects of anticoagulants
may antagonize hemin effect.
Can be detected in plasma up to 5 d. Elimination:
Excess amounts eliminated in bile and urine.
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.