Multiple sclerosis symptoms

Multiple sclerosis (MS) is a chronic autoimmune condition that affects the central nervous system, and its symptoms vary widely from person to person. This article explains the symptoms that medicinal cannabis is most often used for, what the New Zealand evidence and rules say, and how the prescription pathway works under the Medicinal Cannabis Scheme. It does not replace clinical advice. Decisions about treatment must be made with a qualified prescriber.

What the evidence says about cannabis for MS symptoms

The strongest clinical evidence for medicinal cannabis in multiple sclerosis relates to spasticity, followed by certain types of pain and bladder symptoms. Systematic reviews of randomised controlled trials have found moderate-quality evidence that cannabinoids can reduce patient-reported spasticity in MS. The effect size is modest and not every trial shows a clear benefit. The most cited trials used a standardised oral extract containing equal parts THC and CBD (nabiximols, marketed as Sativex in some countries), but in New Zealand prescribing is not limited to that preparation. The Ministry of Health’s Medicinal Cannabis Scheme (operational from April 2020) does not approve specific indications. It regulates quality and access. Clinical decisions are left to the prescriber.

Spasticity evidence in detail

A 2020 systematic review and meta-analysis of 14 RCTs (n=1,652) found that cannabinoids reduced patient-reported spasticity scores significantly compared with placebo, but the effect size was modest (standardised mean difference around 0.3-0.4). The same review found no consistent benefit on objective measures such as the Ashworth scale. Patients may feel improvement without measurable change on clinical examination. A 2022 Cochrane review found similar results for patient-reported symptoms, but noted that many trials were short-term and industry-funded.

Nabiximols (Sativex) is the cannabis-derived medicine with the most robust trial data for MS spasticity. It is an oromucosal spray containing 2.7 mg THC and 2.5 mg CBD per spray. Studies report a 30% or greater reduction in spasticity scores in roughly 30-40% of treated patients compared with placebo. The UK NICE guideline (2019) recommends it as an option for moderate-to-severe spasticity when standard treatments have failed.

A 2021 systematic review in the Journal of Neurology, Neurosurgery & Psychiatry found moderate-quality evidence that cannabinoids reduce patient-reported spasticity in MS, but the effect is modest and not consistent across all measures. The NZ Formulary lists medicinal cannabis preparations for spasticity, explicitly notes “limited evidence,” and advises specialist initiation.

The New Zealand regulatory framework

New Zealand’s Medicinal Cannabis Scheme was established under the Misuse of Drugs (Medicinal Cannabis) Amendment Act 2018. The scheme’s full requirements came into force on 1 April 2020. The Misuse of Drugs (Medicinal Cannabis) Regulations 2019 set out the framework, and the Medicinal Cannabis Agency (MCA) manages licensing and approval. Prescribing is governed by the Misuse of Drugs Act 1975. Medicinal cannabis preparations are classified as prescription medicines under the Medicines Act 1981.

The scheme requires every preparation to meet GMP (Good Manufacturing Practice) standards and be approved by the Ministry of Health. As of 2025, the MCA lists over 100 preparations as meeting the standard. The official register is on the Medicinal Cannabis Agency’s website. It lists every preparation that meets the quality requirement and is a factual source for verifying legality.

Who can prescribe and what they prescribe

Any medical practitioner registered with the Medical Council of New Zealand can prescribe medicinal cannabis preparations that meet the scheme’s standards. They must follow the NZ Formulary guidance. Prescribing is not restricted to specialists. Nurse practitioners cannot prescribe cannabis under the current scheme, except for a narrow set of conditions listed in the Misuse of Drugs Regulations 1977 (a 2023 amendment).

The NZ Formulary includes cannabis monographs. The decision to prescribe is clinical, not formulary-driven. There is no central list of approved conditions. The doctor determines whether a prescription is appropriate after a standard consultation. Prescriptions are issued under Section 25 of the Misuse of Drugs Act 1975, which allows a doctor to prescribe a controlled drug for a patient’s wellbeing. Section 29 of the same Act covers possession for supply, and the Medicinal Cannabis Scheme’s legal framework operates under this section.

The Medsafe-approved list (2024) includes oils, capsules, and flower. All must meet GMP standards. The term “medicinal cannabis” is legally defined as a prescription medicine. It is not a general licence to use cannabis. Raw flower, while available, is prescribed and dispensed through a pharmacy, not a dispensary.

How the patient pathway works

Start with a standard consultation with a registered medical practitioner. The doctor assesses whether a prescription is appropriate. If it is, the doctor writes a prescription under Section 25 of the Misuse of Drugs Act. The patient takes the prescription to a licensed pharmacy, which sources the preparation from a licensed wholesaler. Follow-up and review are part of the pathway. A patient cannot self-refer or buy directly. There is no over-the-counter access.

The newcomer mistake that causes the most trouble is assuming “legal medicinal cannabis” means a patient can legally smoke raw plant material or buy unregulated items. The legal preparation is a manufactured pharmaceutical. Raw flower is prescribed and dispensed through a pharmacy, not a dispensary.

Key agencies and sources

The Medicinal Cannabis Agency (MCA) is part of Medsafe. It issues licences for cultivation, manufacture, supply, and import or export of controlled drugs. It enforces quality requirements, monitors the scheme, and maintains the public register of approved preparations. Medsafe publishes the Medicinal Cannabis Guidance Document and the Product Approval and Quality Standards Guidance. These are the authoritative sources for approval.

The NZ Formulary provides prescribing guidance and lists medicinal cannabis preparations. Healthify, New Zealand’s consumer health resource, provides plain-language information on cannabis medicines and the prescribing pathway.

What the numbers show about prescribing

In 2023, more than 2,500 clinicians had notified prescribing. About 0.5% of New Zealand adults used prescribed medicinal cannabis that year, per the NZ Health Survey. The Ministry of Health reported a 65% increase in supplied preparations from the previous year in 2024.

Safety and driving cautions

Cannabinoids can cause drowsiness, dizziness, and slowed reaction time. Do not drive or operate heavy machinery until you know how a preparation affects you. Discuss any adverse effects with your prescriber immediately. The scheme does not legalise recreational use or home cultivation. Under the Misuse of Drugs Amendment Act 2022 (effective 14 November 2022), the government decriminalised possession of illicit cannabis for personal use. This change does not alter the rules for prescribed cannabis. Possession of a prescribed preparation outside the prescription framework remains unlawful.