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Advice to the Profession: Prescribing Drugs

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Advice to the Profession companion documents are intended to provide physicians with additional information and general advice in order to support their understanding and implementation of the expectations set out in policies. They may also identify some additional best practices regarding specific practice issues.

While prescribing drugs is a standard component of most physicians’ practices, it is also a complex area of clinical care that requires appropriate knowledge, skill, and professional judgment. 

This document is intended to help physicians interpret their obligations as set out in the Prescribing Drugs policy and to provide guidance for how these obligations can be effectively discharged. This document also seeks to provide physicians with practical advice for addressing common issues that arise in practice.

Methadone Maintenance Treatment for Opioid Use Disorder

Methadone maintenance treatment (MMT) is an effective treatment for opioid use disorder. Successful outcomes from MMT require knowledge, experience, vigilance, and diligence on the part of the MMT physician, the patient, and all those involved in treatment.

Physicians must also complete the training necessary to ensure they have the knowledge, skill, and judgment to appropriately prescribe and manage patients through MMT. As with all care and prescribing, physicians will need to exercise sound clinical judgment, taking into consideration the specific needs of their patients. Physicians prescribing methadone for opioid use disorder must do so in accordance with the Prescribing Drugs policy and practice in a manner that is informed by relevant opioid use disorder guidelines.1 In particular, the Centre for Addiction and Mental Health (CAMH) has developed the Canadian Opioid Use Disorder Guideline, a national clinical guideline that standardizes guidelines for Canadian prescribers of opioid agonist therapy, including using methadone.

Mitigating Risk

When initiating MMT, it is important for physicians to be aware of the elevated risk of death from overdoes during the first two weeks of treatment, due to the prolonged half-life and slow bioaccumulation of methadone. As part of initiating treatment, it is important to be clear with patients about what to expect including that it may take several weeks to reach the optimal does and that more frequent visits may be needed during the first two weeks of treatment particularly where patients are at an increased risk of methadone toxicity. Concurrent uses of other drugs (e.g., benzodiazepines, sedatives) or substances (e.g., alcohol) may further increase the risk of death.

Interprofessional collaboration

Regular communication and collaboration between MMT prescribers, pharmacists, and other health-care providers will help ensure patient care is safe and of high quality. This collaboration may include the development of policies and procedures to ensure continuity of patient care and secure custody and storage of methadone.

To optimize care, communication between physicians and pharmacists about the following will be important:

  • Determining at the outset of treatment whether the pharmacy is accepting new patients
  • Discussing how and when the pharmacist is to contact the MMT prescriber including how to reach the prescriber for urgent issues after-hours
  • Documenting or relaying pertinent clinical information (e.g., health changes, missed doses, vomited doses, etc.)

The Ontario College of Pharmacists Key Requirements for Methadone Maintenance Treatment (MMT) factsheet summarizes key requirements for dispensing MMT for pharmacists which will help inform how physicians approach their own practice.

Observing methadone consumption by properly qualified health-care professionals

There may be times where methadone is administered (e.g., provided to the patient for consumption) by a health-care professional other than the prescribing physician. Given the risks associated with methadone, this requires the health-care profession to have particular training and education to ensure they have the knowledge, skill, and judgment to do so safely. Given these risks, generally speaking a health-care professional will need to have completed specific training in the specific and appropriate administration of methadone and have demonstrated an understanding of MMT, including the risks associated with methadone.

Education and training resources

As with all areas of practice, physicians must only prescribe methadone if they have the knowledge, skill, and judgment necessary to do so safely and effectively. Physicians and other health-care professionals can obtain the necessary training and education by completing the Centre for Addiction and Mental Health’s Opioid Use Disorder Treatment course and Opioid Dependence Treatment Certificate Program.2

“Safer supply” opioid prescribing

“Safer supply” opioid prescribing is an emerging area of clinical practice that is grounded in the principles of harm reduction3. It refers to the direct delivery (prescribing) of pharmaceutical-grade opioids to patients with opioid-use disorder as an alternative to the toxic street supply of illicit opioids.

While it can take many forms, safer supply opioid prescribing often involves the prescribing of hydromorphone tablets that are consumed by patients and often without direct supervision by a health care professional.

The College recognizes that providing pharmaceutical-grade alternatives to the toxic street supply, both in the context of a comprehensive treatment plan or as a standalone harm reduction strategy, can enable physicians to support patients with opioid use disorder and reduce their risk of overdose and death. The College also recognizes there have been reports4 that the pandemic has further exacerbated the risks and potential for harm among patients with opioid use disorder. For example, there are indications that the street supply has become increasingly more toxic, leading to a significant increase in opioid related overdoses and deaths and that barriers to access care have worsened as the health care system is under significant strain. As a result, there is a growing interest in exploring emerging or alternative means of treating and supporting this population with an aim to minimize opioid related overdoses and deaths.

As with all opioid prescribing, it is essential that safer supply strategies be implemented in a manner that minimizes the risk of harm and the introduction of unintended consequences that may negatively impact patients (e.g., misuse, abuse) or the public more broadly (e.g., diversion). The need for caution is heightened in the absence of clinical practice guidelines or strong clinical evidence demonstrating the risks and benefits of a particular approach.

If considering safer supply opioid prescribing, physicians are reminded of the following expectations of the current Prescribing Drugs policy:

  • practise within the limits of your clinical competence and/or scope of practice;
  • demonstrate sound clinical judgment, taking into account the individual needs of each patient;
  • consider and apply relevant practice standards, quality standards, and clinical practice guidelines, where they exist;
  • where relevant practice standards, quality standards, and clinical practice guidelines do not exist, or in areas of medicine that are less developed, consider the best available indirect evidence, including clinical trials and evidence-based research to help inform consensus protocols or best practices;
  • review previous interventions the patient has undergone; and
  • develop a comprehensive treatment plan that can help the patient while minimizing risks and unintended consequences (e.g., the risk of diversion).

Physicians are further reminded that the importance of careful documentation increases as care departs from recommended guidelines and/or moves into areas of medicine that are less developed.

Accessing patients’ electronic prescription histories

The Prescribing Drugs policy requires that, prior to initiating a prescription for a narcotic or controlled substance, physicians must take reasonable steps to review the patient’s prescription history (provision # 32, e).

As an example, the policy suggests (but does not require) that this could include reviewing electronic sources of information regarding the patient’s prescription history (e.g., via provincial prescribing databases), where these are available.

Access to this information at the point of care continues to evolve and many physicians in Ontario are now able to access valuable information about their patient’s prescription histories electronically via the Digital Health Drug Repository (DHDR).

The DHDR supports authorized healthcare providers’ secure electronic access to a patient’s available drug and pharmacy service information, enabling prescribers to develop the best possible medication history at the point of care.

Information available via the DHDR currently includes:

  • dispensed publicly-funded drugs;
  • publicly-funded pharmacy services (e.g., MedsCheck program; influenza vaccinations);
  • non-publicly funded drugs and pharmacy services (e.g., funded by private insurance); and
  • all dispensed monitored drugs, including narcotics and controlled substances (when the approved identification used was a valid Ontario Health number).

The DHDR is currently available through electronic medical record (EMR) systems certified by Ontario MD and two provincial clinical viewers:

  1. DHDR EMR Integration (OntarioMD can provide access through your practice’s EMR);
  2. ClinicalConnect5 in South West Ontario; and
  3. ConnectingOntario Clinical Viewer6 in the Greater Toronto Area, and Northern and Eastern Ontario.

For more information about the DHDR, including information on how to sign up to access these systems, please see eHealth Ontario’s website.

The College will continue to monitor the landscape for new electronic sources of information regarding patient’s prescription histories and will update this Advice Document to support safe and effective prescribing.

Considering prescription drug costs

Available research shows that a failure to consider prescription drugs costs at the point of care can have a variety of unintended negative consequences, including that:

  • many prescriptions go unfilled because the patient is unable to afford them;
  • many patients do not take their medications as prescribed due to cost; and
  • high prescription drug costs are associated with increased clinic, emergency room visits, and hospitalizations.

For this reason, physicians may wish to consider on a proactive basis:

  • the cost of the drugs they prescribe, and
  • whether there is a therapeutically equivalent alternative that is available at a lower price.

This analysis will be particularly important when a physician has reason to believe that their patient may struggle to afford or be unable to pay for the drug being prescribed.

The College is aware that physicians do not currently have convenient or up-to-date access to information regarding the cost of prescription drugs. As resources become available to support physicians in considering prescription drug costs, the College will seek to make these resources available.

Prescription treatment agreements (e.g., “narcotics prescribing contracts”)

­Prescription treatment agreements (sometimes called narcotics prescribing contracts) are formal and explicit written agreements between physicians and patients that delineate mutual expectations for continued prescribing.

Treatment agreements are usually employed to help promote compliance with an agreed-upon set of conditions for the continued prescribing of drugs with a potential for abuse, misuse, and diversion, such as prescription opioids.

As the proposed benefits of treatment agreements are limited by low-quality evidence, they are not currently required or endorsed by the CPSO nor are they recommended by the 2017 Canadian Guideline for Opioids for Chronic Non-Cancer Pain; however, physicians may use them in keeping with their own professional judgment.

Where physicians elect to use treatment agreements in support of safe and effective prescribing, best practice would suggest using them as an educational tool, rather than a punitive one. In this way, treatment agreements may help to ensure that patients understand the circumstances in which they will or will not receive a prescription, while avoiding creating a power imbalance that could undermine the physician-patient relationship.

Reporting adverse drug reactions or medication incidents7

Physicians can help support the ongoing evaluation of prescription drug safety by reporting adverse drug reactions8, suspected adverse drug reactions, and medication incidents9 to the relevant organizations, especially those that are:

  • unexpected, regardless of their severity;
  • serious,10 whether expected or not; and
  • related to recently marketed health products (on the market for less than five years).

Physicians can report adverse drug reactions to Health Canada’s Vigilance Program at and medication incidents through the Institute for Safe Medication Practices Canada:

Physicians can also encourage their patients to report any medication incidents at

Prescription drug disposal

Because most community pharmacies have procedures in place to safely dispose of patient returned medications (also called post-consumer waste), it is generally best practice for physicians to direct patients to their local pharmacy to return unused medication.

In circumstances where a physician takes possession of the patient’s drugs directly or is in possession of any other types of medications (e.g., unused or expired medication samples), physicians can contact a drug disposal company to set up their own contract for safe disposal. Physicians may further consider arranging for the disposal of unused/expired/returned drug samples directly through the pharmaceutical representative or company that has provided them.


1. For example, the Canadian Research Initiative in Substance Misuse National Guidelines for the Clinical Management of Opioid Use Disorder and Health Quality Ontario’s Opioid Use Disorder Quality Standard.

2. Other equivalent education may be available, for example, see the Mental Health Commission of Canada’s list of opioid training resources in Canada.

3. “Harm reduction” refers to evidence-based, patient-centred approaches to care that seek to reduce the health and social harms associated with addiction and substance use but do not necessarily require people who use substances to abstain from them.

4. See for example the Minister Hajdu’s “Letter from the Minister of Health regarding treatment and safer supply” and the synthesis of the available evidence laid out therein.

5. Clinical connect is a secure, web-based portal that gives health care providers real-time access to the patients’ electronic medical information from all acute care hospitals, Local Health Integration Networks’ (LHIN) Home and Community Care Services, and Regional Cancer Programs in South West Ontario, in addition to various provincial clinical data repositories.

6. The Connecting Ontario Clinical Viewer is a secure, web-based portal that provides real-time access to digital health records including dispensed medications, laboratory results, hospital visits, Local Health Integration Networks’ (LHIN) Home and Community Care Services, mental health care information, and diagnostic imaging reports and images.

7. In addition to reporting any adverse drug reactions or medication incidents, physicians can find additional requirements for reporting (as applicable) in the College’s Disclosure of Harm policy.

8. Adverse drug reactions are unwanted effects that happen when drugs are used under normal conditions. Adverse drug reactions are also called side effects. Adverse drug reactions are not medication incidents. Unlike a medication incident, an adverse drug reaction generally doesn’t involve a mistake and typically can’t be prevented.

9. A medication incident is a mistake with medication, or a problem that could cause a mistake with medication. ‘Medication error’ is another name for one kind of medication incident. Medication incidents include obvious things like receiving the wrong medication or dose, but might also include problems like a confusing label that might lead to someone receiving the wrong medication.

10. Health Canada’s Adverse Reaction Information webpage describes a serious adverse drug reaction as one that requires in-patient hospitalization or prolongation of existing hospitalization, causes congenital malformation, results in persistent or significant disability or incapacity, is life-threatening or results in death. Adverse reactions that require significant medical intervention to prevent one of these listed outcomes are also considered to be serious.