News

Calculating renal function: eGFR or CrCl?

estimated Glomerular Filtration Rate (eGFR; units mL/min/1.73m2) is often used in practice for determining renal function since it is readily available via lab results. It should be adjusted for body surface area  in individuals with extremes of size. Alternatively, the Cockcroft-Gault formula (CrCl) can be used.

For more background information, see:

– recent MHRA article. Note they refer to eGFR as the reported lab value (mL/min/1.73m2) rather than adjusting for the individual patient’s body surface area.

– our section on Prescribing in Renal Impairment or the CDHB Pink Book guidelines (Canterbury only).

Ranitidine recall update (09/12/19)

The availability of ranitidine is extremely limited. Famotidine IV/oral is currently funded for hospital use, and 20 mg tablets will be fully funded in community from 1st January 2020 under Section 29 (unlicensed medicine). 

See Medsafe’s statement for more details on the product recall – https://www.medsafe.govt.nz/safety/Alerts/MedicinesAndNDMA.asp 

 

Alternative management options include:

Gastroesophageal reflux disease (GORD):

  • consider trialling cessation of H2-antagonist therapy
  • lifestyle modification (e.g. avoiding foods that trigger symptoms, such as alcohol and caffeine)
  • antacids e.g. aluminium (e.g. Alu-tab 600 mg tablets – fully funded)
  • alginates (Gaviscon Double Strength®tablets and Acidex® liquid – partially funded)
  • proton-pump inhibitors – omeprazole, pantoprazole and lansoprazole are all fully funded. Also suitable to use in pregnancy
  • See HealthPathways for more guidance https://canterbury.communityhealthpathways.org/24341.htm  (Canterbury only)

 

Chronic urticaria: 

Withdrawal of dosulepin (dothiepin) and doxepin from New Zealand

Two tricyclic antidepressants (TCAs), dosulepin (dothiepin) and doxepin will no longer be available in New Zealand.

When transitioning patients to alternatives, consider:

  • Is a TCA still appropriate? TCAs are associated with a higher risk of adverse outcomes in people with cardiovascular disease and older adults.
  • Individual psychiatric history. Switching therapy increases the risk of relapse of mental illness and psychosocial support and/or referral may be needed.
  • Antidepressant discontinuation syndrome. TCAs are associated with discontinuation symptoms, particularly if stopped abruptly after more than 4 weeks of regular use.
  • Individual TCAs are not dose equivalent. Dose titration may be needed when switching to another TCA.
  • Dosulepin (dothiepin) and doxepin are sedating antidepressants, switching to a less-sedating antidepressant (e.g. SSRI, nortriptyline) may cause sleep problems.

For general information on switching antidepressants, discontinuation symptoms and their relative adverse effects see nzf.org.nz/nzf_2225. Health professionals are also welcome to contact our service for more specific or detailed advice on switching therapy.

Notifications from PHARMAC regarding the withdrawal of these medicines:

Pregabalin is now fully funded

Pregabalin is a gabapentinoid that is now fully funded and indicated as an option for patients with neuropathic pain, as well as focal seizures and generalised anxiety (unlicensed). Pregabalin may offer advantages over gabapentin in patients where adherence to a three-times-daily regimen is problematic or where gastrointestinal absorption may be impaired. The efficacy of gabapentinoids should be reviewed after initiation and dose escalations, as many patients obtain minimal benefit but experience adverse effects. Gabapentinoids also have the potential to be abused. For more information, see the bulletin published by the CDHB Analgesic Stewardship Committee on our website.