Usual Adult Dose for Porphyria

1 to 4 mg/kg/day IV over at least 30 minutes for 3 to 14 days based on clinical signs; in more severe cases, this dose may be repeated no earlier than every 12 hours

• Maximum dose: 6 mg/kg per 24 hours

• This drug is indicated for the amelioration of recurrent attacks of acute intermittent porphyria temporally related to the menstrual cycle in susceptible women; pain, hypertension, tachycardia, abnormal mental status, and mild to progressive neurologic signs may be controlled in patients with this disorder
• Similar findings have been reported in other patients with acute intermittent porphyria, porphyria variegata, and hereditary coproporphyria (this drug is not indicated in porphyria cutanea tarda)

Usual Pediatric Dose for Porphyria

16 years and older:
1 to 4 mg/kg/day IV over at least 30 minutes for 3 to 14 days based on clinical signs; in more severe cases, this dose may be repeated no earlier than every 12 hours

• Maximum dose: 6 mg/kg per 24 hours

• This drug is indicated for the amelioration of recurrent attacks of acute intermittent porphyria temporally related to the menstrual cycle in susceptible women; pain, hypertension, tachycardia, abnormal mental status, and mild to progressive neurologic signs may be controlled in patients with this disorder
• Similar findings have been reported in other patients with acute intermittent porphyria, porphyria variegata, and hereditary coproporphyria (this drug is not indicated in porphyria cutanea tarda)

Renal Dose Adjustments

Data not available

Liver Dose Adjustments

Data not available

Precautions

US BOXED WARNINGS:

• This drug should only be used by physicians experienced in the management of porphyrias in hospitals where the recommended clinical and laboratory diagnostic and monitoring techniques are available.
• Therapy with this drug should be considered after an appropriate period of alternate therapy (i.e., 400 g glucose/day for 1 to 2 days).

• Hypersensitivity to the active component or any of the ingredients

Dialysis

Data not available

Other Comments

Administration advice:

• Before administering this drug, a period of alternate therapy (i.e., 400 g glucose/day for 1 to 2 days) should be considered.
• For moderate to severe attacks, immediate treatment with this drug is recommended. Symptoms of severe attacks are severe or prolonged pain, persistent vomiting, hyponatremia, convulsion, psychosis, and neuropathy.
• Therapy with this drug is not curative. After discontinuation of therapy, symptoms generally return although in some cases remission is prolonged. Some neurological symptoms have improved weeks to months after therapy although little or no response was noted at the time of treatment.

• Store lyophilized powder at 20C to 25C (68F to 77F).

• Reconstitute this drug by aseptically adding 43 mL of Sterile Water for Injection, to the dispensing vial.
• Immediately after adding diluent, shake well for 2 to 3 minutes.
• Because this drug contains no preservative and because it undergoes rapid chemical decomposition in solution, it should not be reconstituted until immediately before use.
• After the first withdrawal from the vial, any solution remaining should be discarded.

• This drug is compatible with Sterile Water for Injection.
• No drug or chemical agent should be added to this drug admixture unless its effect on the chemical and physical stability has first been determined.

• Before initiating therapy, the presence of acute porphyria should be diagnosed using the following criteria: Presence of clinical symptoms, positive Watson-Schwartz or Hoesch test (a negative Watson-Schwartz or Hoesch test indicates a porphyric attack is highly unlikely); when in doubt quantitative measures of delta-aminolevulinic acid and porphobilinogen in serum or urine may aid in diagnosis.

• Delta-aminolevulinic acid (ALA)
• Uroporphyrinogen (UPG)
• Porphobilinogen (PBG)
• Coproporphyrin