RxFiles Q&As


Our Q&As are a guide to clinical controversies. Commonly asked questions are answered with the evidence available at the time of publication.

HIV Medications and Drug Interactions
April 2021

What are some common drug interactions with HIV medications?

Which HIV medications have the most interactions?

What are some examples of CYP inducers and inhibitors that interact with HIV medications?

Buprenorphine-Naloxone (SUBOXONE)
September 2020

What benefits might buprenorphine-naloxone offer in the treatment of opioid use disorder?

What are the adverse effects associated with buprenorphine?

What is precipitated withdrawal?

How is buprenorphine-naloxone therapy initiated?

How is buprenorphine-naloxone administered?

Antibiotic Harms
July 2020

How common are overall harms with antibiotics?

How common are allergic reactions with antibiotics?

How common are serious harms with antibiotics?

What about antimicrobial resistance? 

ASA: When to Prescribe
December 2019

Should ASA be used for primary prevention?

VACCINES: Pneumococcal, Influenza, & Shingles
July 2019

Who may benefit from a PNEUMOCOCCAL vaccine?

Who may benefit from an INFLUENZA vaccine?

Who may benefit from a SHINGLES vaccine?

Topical Cannabis: Does it Live Up to its Presumed Potential?
June 2019

What is topical cannabis? Why would someone use it?

Has topical cannabis been proven to work?

Why might my patient report improvement with topical cannabis if the evidence for benefit is so weak?

Is topical cannabis dangerous?

How do my patients access these products? 

SHINGRIX (recombinant zoster vaccine)
April 2018

What is SHINGRIX? Is SHINGRIX effective?

What are potential adverse events, contraindications, and drug interactions with SHINGRIX?

Is SHINGRIX cost-effective?

How long after shingles can a herpes zoster vaccine be given?

How is SHINGRIX supplied and dosed?

How does SHINGRIX compare to ZOSTAVAX?

Cystitis and Pyelonephritis
March 2017

What percentage of patients with uncomplicated cystitis go on to develop pyelonephritis?

Nitrofurantoin and Peripheral Neuropathy
March 2017

What is the risk of peripheral neuropathy with nitrofurantoin (MACROBID)? 

Nitrofurantoin and Pulmonary Toxicity
March 2017

What is the risk of pulmonary toxicity with nitrofurantoin (MACROBID)? 

Clopidogrel + ASA
March 2016

Does clopidogrel (PLAVIX) + ASA (ASPIRIN) impact mortality?

Clinical Practice Guidelines
June 2015

What is the value, role, and limitation of clinical practice guidelines?

Bioequivalency of Medications
April 2015

Are brand name and generic medications the same?

Orthostatic Hypotension
June 2014

What is orthostatic hypotension? What is its prevalence?

What causes orthostatic hypotension?

What is neurogenic orthostatic hypotension?

What is the overall goal of orthostatic hypotension management?

What medications may worsen orthostatic hypotension?

How should orthostatic hypotension be managed?

Hypertensive Urgency
April 2014

What is hypertensive urgency and how does it compare to hypertensive emergency?

What causes hypertensive urgency?

How should hypertensive urgency be managed?

What are the drug considerations for hypertensive urgency?

What are the follow-up and monitoring parameters for hypertensive urgency?

What about immediate-release nifedipine?

Chronic Insomnia in Older Adults
October 2013

How can chronic insomnia be managed in older adults?

Pharmacists and Opioids
June 2013; updated December 2017

What can pharmacists do to address both pain and addiction/diversion concerns? 

Dabigatran and Myocardial Infarction
June 2013

Does Dabigatran (PRADAX) increase the risk of myocardial infarction?

Statin Intolerance
June 2013

How can statin intolerance be managed? 

Bipolar in Pregnancy
February 2013

Should mood stabilizers be used before, during, or after pregnancy?

What is the risk of bipolar relapse during pregnancy and postpartum?

Is there any harm in not treating bipolar disorder during pregnancy and postpartum?

What is the role of non-pharm therapies during pregnancy and postpartum?

Which mood stabilizers are safest in pregnancy?

How should acute depression and manic episodes be managed in pregnancy?

Should females with bipolar disorder breastfeed?

Bacterial Vaginosis and Pregnancy
February 2013

What obstetric & gynecological complications are associated with bacterial vaginosis in pregnancy?

Should bacterial vaginosis be screened for during pregnancy?

Who should be treated for bacterial vaginosis during pregnancy?

How should bacterial vaginosis be treated in pregnancy?

Are there any harms to treating bacterial vaginosis with antibiotics?

Is metronidazole safe in pregnancy and breastfeeding?

Is clindamycin safe in pregnancy and breastfeeding?

Mild Hypertension
October 2012

Does mild hypertension need to be treated?

Opioid-Induced Constipation
October 2012

Do certain opioids or routes of administration cause less constipation?

Should oxycodone + naloxone (TARGIN) be used to reduce opioid-induced constipation?

Should methylnaltrexone (RELISTOR) be used to reduce opioid-induced constipation?

Does constipation impact the absorption of sustained-release oral opioids?

Does oxycodone + naloxone (TARGIN) reduce oxycodone's analgesia?

Individualizing Glycemic Targets in the Frail Elderly
April 2012

How can glycemic targets be individualized for frail older adults?

Antidepressants in Pregnancy & Breastfeeding
April 2012

Should antidepressants be discontinued before or during pregnancy?

Is there any harm in not treating depression and/or anxiety during pregnancy & postpartum?

What is the role for non-pharmacological therapies during pregnancy & postpartum period? When should antidepressants be considered?

Which antidepressants are considered the safest during pregnancy?

Does paroxetine cause congenital malformations when used in the first trimester? Do SSRIs cause persistent pulmonary hypertension of the newborn? Do antidepressants cause neonatal behavioural syndrome?

Which antidepressants are considered safe during breastfeeding?

What are some other important considerations in the management of depression & anxiety during pregnancy? 

Diabetes in Pregnancy
March 2012

What are the complications of diabetes in pregnancy?

What are the glycemic targets for diabetes in pregnancy?

Which treatments are recommended for diabetes in pregnancy and gestational diabetes?

Which insulins are safe to use in pregnancy?

Can oral hypoglycemic agents be used in pregnancy?

What are some other important considerations in the management of diabetes in pregnancy?

Opioids in Older Adults
March 2011

What are the risks or potential problems when using opioids in the elderly?

What precautions should be taken for a more cautious opioid initiation in the elderly?

What are some pros and cons to various analgesics in the elderly?

YAZ / YASMIN Safety Considerations
January 2011

What is Yaz / Yasmin? Which products are available in Canada?

What is drospirenone?

What has sparked public concern over the safety of Yaz / Yasmin?

What is a typical woman's risk for VTE? 

What do we know about drospirenone and the risk of VTE? 

What are other potential safety concerns related to drospirenone use?

Evidence for Vitamin D
November 2010; updated November 2017

What is the evidence for the various potential indications of Vitamin D?

Energy Drinks
December 2010

What are the common ingredients found in energy drinks?

Why the trend to consume these beverages? Do energy drinks deliver results?

What are the recommended limits for caffeine consumption?

How are these products regulated in Canada? 

What variations are available on the market? How much do energy drinks cost?

Are energy drinks safe to consume?

Is it safe to mix energy drinks with alcohol? How do you feel about Alert & Dangerous?

BuTrans Patches
September 2010

What is the appropriate use of the BuTrans patch?

Zostavax (live zoster vaccine)
October 2009; updated April 2014

What is ZOSTAVAX? Is it effective?

What are potential adverse events and drug interactions with ZOSTAVAX?

What are other potential cautions regarding the use of ZOSTAVAX

Is administration of ZOSTAVAX cost effective? 

What are the Current Vaccination Recommendations for ZOSTAVAX?

How is ZOSTAVAX supplied? What is the dosage and how is it administered? 

Clopidogrel & PPIs
January 2009

What is the concern regarding co administration of clopidogrel with a proton pump inhibitors (PPIs)?

What is the proposed mechanism of this potential drug interaction?

How well documented is this potential drug interaction? 

 Do all PPIs interact with clopidogrel?

How should I manage patients currently receiving clopidogrel with a PPI?  

What about other drugs that inhibit the CYP2C19 enzyme?

ACEI & ARB Combinations
January 2009

Does combining an ACEI and ARB cause harm?

November 2008

What is sitagliptin?

How much does sitagliptin improve A1C & glucose levels?

What is the effect of sitagliptin on weight?

Does sitagliptin cause hypoglycemia?

What are other potential adverse effects with sitagliptin?

What are other potential cautions regarding the use of sitagliptin?

Metformin and Lactic Acidosis
October 2008; updated August 2019

Why is metformin considered in patients with a potential caution or contraindication?

What is the risk of metformin associated lactic acidosis?

What conditions or risk factors predispose patients to lactic acidosis?

Can metformin be used in patients with reduced kidney function/chronic kidney disease?

Can metformin be used in patients with hepatic dysfunction?

Is metformin safe to use in patients with heart failure?

Rosiglitazone (AVANDIA) and Cardiovascular Risk
May 2007

Should we be concerned about cardiovascular risk with rosiglitazone?

November 2004

Are statins overused or underused?

Should high-dose statins be used in high-risk patients?

What's the objective take on the rosuvastatin controversies?

March 2003

How does the Australian (ANBP2) trial compare to the North American (ALLHAT)?

November 2002

How to interpret the results of the WHI in hormone replacement therapy? 

HRT & Breast Cancer
September 2002

Does hormone replacement therapy increase the risk of breast cancer? 

Creatinine Kinase & Statins
March 2002

Is it necessary to monitor creatinine kinase for patients on a statin?

Hypoglycemic Drug Interactions
October 2001

What drugs should not be used in combination with oral hypoglycemics?

Since many diabetics have or develop concurrent cardiovascular disease, what effect do cardiac medications have on hypoglycemic efficacy? 

February 2001

Is meloxicam COX-2 selective?

September 2000

A patient guide to preventing and treating influenza.

Asthma Alternate Therapies
May 2000

What is the evidence for herbal/alternative therapies in asthma?

Diane 35
March 2000

What is Diane 35?

How does Diane 35's contraceptive effect compare to other OCs?

What is Diane 35's role in treatment of acne relative to other OCs? 

Chronic Unopposed Vaginal Estrogen
October 1999

Is chronic unopposed vaginal estrogen therapy safe?

"Natural" Hormone Replacement Therapy
September 1999

Is natural hormone replacement therapy safe or effective?

Fluoxetine & PMS
December 1998

Is fluoxetine effective in PMS?

St. John's Wort
November 1998

Is St. John's Wort effective for depression?

What precautions should be observed when using St. John's Wort?

Diuretics & Hypertension
March 1998

When are thiazide diuretics considered first-line antihypertensives?

Are low doses thiazides as effective in treating hypertension as higher doses?

What about the adverse metabolic effects of thiazides?

How do thiazides compare to calcium channel blockers, ACE inhibitors, and other antihypertensives?