Article 18 - Side Effects, Titration, and When to Seek Help

Every medicine can produce unwanted effects. The useful question is not whether a cannabis-based medicine has zero risk. It is how to recognise changes, record them clearly, and get the right help at the right time.

Side effects can appear when treatment starts, after a dose or product change, or when another medicine is added. Some are temporary and manageable. Others need a prompt clinical review. A small number require urgent or emergency help.

What counts as a side effect?

A side effect is an unwanted or unexpected response that occurs during treatment. It may be mild or severe, short-lived or persistent. It may also be difficult to separate from an underlying symptom, another medicine, an illness, or a change in sleep and stress.

Do not assume that every new symptom is caused by cannabis-based medicine. Do not dismiss a symptom simply because the medicine is prescribed. Record what happened and discuss it with the appropriate healthcare professional.

Effects that may affect daily function

Some patients may experience drowsiness, dizziness, changes in concentration, altered perception, dry mouth, nausea, changes in appetite, anxiety, or reduced coordination. The likelihood and severity depend on the product, dose, route, timing, patient, and other medicines or substances.

If you feel drowsy, dizzy, confused, unsteady, or impaired, do not drive, operate machinery, work at height, or carry out safety-critical activities. Sit or rest somewhere safe and follow the advice supplied by your prescribing team.

What to record

A clear record can help a clinician decide whether the symptom relates to the product, the dose, the timing, or another factor. Record:

• Product name, strength, and formulation
• Amount used and time taken
• Route and delivery method
• When the symptom started
• How long it lasted
• How severe it felt
• Any benefit noticed
• Other medicines, alcohol, or substances used
• Changes in sleep, food, illness, stress, or routine

Use plain language. “Felt unsteady for two hours after the evening dose” is more useful than “did not feel right.”

What titration has to do with side effects

Titration means adjusting a medicine carefully to find an acceptable balance between benefit and unwanted effects. It should follow the plan set by the prescribing clinician or clinic.

If unwanted effects increase after a change, do not keep increasing the amount to chase a stronger benefit. Contact the prescribing team and explain what changed. The plan may need review, but the correct response depends on the medicine and the individual situation.

Do not copy another patient's dose and do not treat a product's headline strength as a personal dosing instruction.

When to contact your prescribing team

Contact the clinic, pharmacist, or prescribing clinician if:

• A side effect is persistent, worsening, or affecting daily life
• You feel impaired or unsafe after using the medicine
• You are using more than the prescribed plan
• The benefit has changed consistently
• You have started or stopped another medicine
• The product, batch, device, or formulation has changed
• You are unsure whether to continue, pause, or change the plan

Have the product packaging, batch details, medicines list, and treatment record available where possible.

When urgent help may be needed

Seek urgent medical advice for severe or rapidly worsening symptoms, significant confusion, severe agitation, fainting, chest pain, serious breathing difficulty, severe allergic symptoms, or another symptom that feels like an emergency.

If someone is unconscious, having severe difficulty breathing, experiencing a seizure, or in immediate danger, contact emergency services. Do not wait for a routine clinic response.

Do not drive yourself if you are impaired. Tell the healthcare professional what was taken, how much, when it was taken, and what other medicines or substances may have been involved.

Do not hide a difficult experience

Patients sometimes worry that reporting a side effect will lead to judgement or automatic loss of treatment. Accurate reporting is part of safe clinical care. It gives the team a chance to review the product, dose, route, interactions, storage, and wider health picture.

Be honest about missed doses, additional use, alcohol, other substances, and changes made outside the plan. The goal is not to assign blame. It is to understand what happened and reduce the chance of it happening again.

Side effects and driving

Feeling well enough to drive is not the same as being legally or clinically safe to drive. A patient should never drive while impaired. Follow the advice from the prescribing team and the legal requirements that apply to prescribed medicines and driving.

Keep the relevant prescription and medicine documentation available when appropriate, but do not treat documentation as permission to drive while unfit.

The honest conclusion

Side effects should be taken seriously without being treated as proof that treatment has failed. The safest approach is to observe, record, communicate, and seek help at the right level.

Titration is individual and clinically supervised. Mild or uncertain changes may need a routine discussion. Persistent or worsening problems need prompt review. Emergency symptoms need urgent help immediately.

Sources and further reading

This article is general patient education and does not diagnose or triage an individual medical problem. For advice about your treatment, contact your prescribing clinician or pharmacist. For an emergency, contact emergency services.