Published: 4 June 2020

Publications

Gathering knowledge from adverse reaction reports: June 2020

Prescriber Update 41(2): 32–33
June 2020

Adverse reaction reporting is an important component of medicine safety monitoring. Case reports can highlight significant safety issues concerning therapeutic products and their use.

The table below presents a selection of recent informative cases from the Centre for Adverse Reactions Monitoring (CARM) database.

Case detailsa,b	Reaction description and data sheet informationb,c
CARM ID: 134546 Age: 54 Gender: Female Medicine(s): Terbinafine Reaction(s): Systemic lupus erythematosus	Two months after starting oral terbinafine, the patient experienced a worsening eczematous rash across her abdomen, back and lower limbs. Laboratory results were positive for antinuclear antibodies, anti-Ro antibody and anti-histone antibody. She was diagnosed with terbinafine-induced lupus (flare of subacute cutaneous lupus erythematosus) and treated with topical clobetasol.
	The Deolate data sheet lists cutaneous and systemic lupus erythematosus as very rare adverse reactions.
CARM ID: 135335 Age: 39 Gender: Male Medicine(s): Atorvastatin Reaction(s): Pancreatitis	Three weeks after starting atorvastatin, the patient experienced abdominal pain, with laboratory tests showing raised amylase and bilirubin, and deranged LFTs. He was diagnosed with pancreatitis and the atorvastatin was discontinued.
	Liver derangements are well known with statins, and pancreatitis is listed as a rare adverse reaction in the Lorstat data sheet. See also the Prescriber Update article about pancreatitis.
CARM ID: 135630 Age: 55 Gender: Female Medicine(s): Flucloxacillin Reaction(s): Lip swelling, pruritis, urticaria	The patient experienced a delayed allergic reaction to flucloxacillin, with a rash appearing on the fifth day of treatment and lip swelling two days after stopping treatment.
	Allergic reactions, including rash, urticaria and angioedema, are described in the Staphlex data sheet. See also the Prescriber Update article about delayed skin reactions reported with penicillins.
CARM ID: 136107 Age: 64 Gender: Female Medicine(s): Zoledronic acid Reaction(s): Hypophosphataemia, malaise, vision blurred	Soon after receiving a zoledronic acid infusion, the patient reported symptoms of bloating, nausea and loss of appetite. This progressed to difficulty breathing, weakness, fever, chills, blurred vision and pain in her neck and shoulders. Seven days after the infusion, she was diagnosed with hypophosphataemia and treated with oral phosphate replacement therapy.
	The Aclasta data sheet lists hypophosphataemia as an adverse reaction derived from post-marketing experience, with an unknown frequency.
CARM ID: 136158 Age: 77 Gender: Male Medicine(s): Methotrexate, sulfamethoxazole + trimethoprim (Co-trimoxazole) Reaction(s): Drug interaction, pancytopenia	While on treatment with methotrexate, the patient was prescribed co-trimoxazole. The patient subsequently experienced pancytopenia and methotrexate toxicity.
	The Trexate and Trisul data sheets state that methotrexate and co-trimoxazole have anti-folate effects. Co-trimoxazole (and trimethoprim alone) may also increase the free plasma levels of methotrexate by inhibiting renal excretion. Co-administration may therefore lead to increased bone marrow suppression. If co-trimoxazole is considered appropriate therapy in patients receiving other anti-folate drugs such as methotrexate, a folate supplement should be considered, and the full blood count closely monitored.

Notes:

1. Only the medicines suspected to have caused the reaction are listed in the table.
2. The reactions listed in the ‘Case details’ column are coded according to the Medical Dictionary for Regulatory Activities (MedDRA), an internationally used set of standardised terms relating to medical conditions, medicines and medical devices. The reactions listed in the ‘Reaction description’ column are based on what was reported to CARM, and do not always match the MedDRA term.
3. If the suspect medicine’s brand name is not described in the report to CARM, only the data sheet for the funded medicine is included in the table.

Information about suspected adverse reactions reported to CARM is available on the Medsafe website using the Suspected Medicines Adverse Reaction Search (SMARS).

By selecting the ingredient of a medicine, you can find out:

• the number of reports and suspected adverse reactions for that ingredient. The suspected reactions are grouped by body system or organs (Summary report)
• single case reports, listing the medicines involved that contain the ingredient and the suspected adverse reactions (Detail report).