CARM ID: 123194

Age: 29

Gender: Female

Medicine(s): Jadelle, Rifampicin

Reaction(s): Unintended pregnancy

The unintended pregnancy occurred approximately one year after Jadelle insertion and about six months after starting rifampicin.

The Jadelle data sheet (www.medsafe.govt.nz/profs/Datasheet/j/Jadelleimplant.pdf) states that rifampicin diminishes the efficacy of Jadelle by enzyme induction. Enzyme induction can be observed within a few days of treatment and may be sustained for about four weeks after cessation of the inducer.

CARM ID: 123149

Age: 15

Gender: Male

Medicine(s): Sodium valproate

Reaction(s): Hyperammonaemia

The patient experienced hyperammonaemia encephalopathy. On review, the patient was found to have an elevated sodium valproate level and five times normal range of ammonia in blood.

The sodium valproate data sheet (www.medsafe.govt.nz/profs/Datasheet/e/Epilimtabsyrliqiv.pdf) notes hyperammonaemic encephalopathy, sometimes fatal, has been reported following initiation of valproate therapy in patients with urea cycle disorders, a group of uncommon genetic abnormalities, particularly ornithine transcarbamylase deficiency. Patients who develop symptoms of unexplained hyperammonaemic encephalopathy while receiving valproate therapy should be evaluated for underlying urea cycle disorders.

CARM ID: 123120

Age: 78

Gender: Female

Medicine(s): Venlafaxine

Reaction(s): Hyponatraemia

Five days after starting venlafaxine the patient’s serum sodium had dropped to below 120 mmol/L. A week after discontinuing venlafaxine, the patient’s serum sodium levels had returned to baseline.

The data sheet for venlafaxine (www.medsafe.govt.nz/profs/Datasheet/e/Efexorxrcap.pdf) states cases of hyponatraemia may occur with venlafaxine. Elderly patients, patients taking diuretics and patients who are otherwise volume depleted, may be at greater risk for this event. These have resolved on discontinuation of the drug.

CARM ID: 120887

Age: 12

Gender: Male

Medicine(s): Prednisone, Methylprednisolone, Hydrocortisone

Reaction(s): Bilateral cataracts

The patient’s severe eczema was treated with topical and systemic steroids. The patient developed bilateral cataracts with vision reduced to light perception.

The prednisone data sheet (www.medsafe.govt.nz/profs/Datasheet/a/Apoprednisonetab.pdf) states that prolonged use of corticosteroids may produce subcapsular cataracts and nuclear cataracts (particularly in children).