International Journal of Community Medicine and Public Health

Lokhande N et al. Int J Community Med Public Health. 2025 Jun;12(6):2894-2899

http://www.ijcmph.com

pISSN 2394-6032 | eISSN 2394-6040

Review Article

DOI: https://dx.doi.org/10.18203/2394-6040.ijcmph20251740

From relief to risks: a comprehensive review of medical cannabis

Nidhi Lokhande1, Aditya Mokal1, Namita Deshmukh2, Avinash Borkar2*, Suvarna Patil3

1BKL Walawalkar Rural Medical College, Ratnagiri, Maharashtra, India

2Department of Community Medicine, Dr Rajendra Gode Medical College, Amravati, Maharashtra, India

3Department of General Medicine, BKL Walawalkar Rural Medical College, Ratnagiri, Maharashtra, India

Received: 10 March 2025

Revised: 21 May 2025

Accepted: 22 May 2025

*Correspondence:

Dr. Avinash Borkar,

E-mail: avigod.7@gmail.com

Copyright: © the author(s), publisher and licensee Medip Academy. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

ABSTRACT

Cannabis has been used for medicinal purposes for thousands of years, with a resurgence in modern medical applications sparking significant research and regulatory discussions. This review explores the medical benefits, risks, mechanisms of action, and legal considerations of cannabis use. Cannabis-based treatments have shown efficacy in managing multiple conditions, including chronic pain, multiple sclerosis, psychiatric disorders, chemotherapy-induced nausea, epilepsy, and neurodegenerative diseases. Despite its therapeutic potential, cannabis use carries short- and long-term risks, including cognitive impairment, cardiovascular issues, dependency, and adverse mental health effects. The variability in cannabis products, dosing, and regulation raises concerns regarding safety and quality control. Additionally, ethical dilemmas exist in prescribing unstandardized cannabis-based therapies. Legalization trends across various regions continue to shape the accessibility and acceptance of medical cannabis, though significant research gaps remain. Future studies are required to further validate its efficacy, optimize dosing strategies, and mitigate potential health risks. This review provides a comprehensive overview of current evidence, highlighting both the promise and challenges associated with medical cannabis.

Keywords: Clinical research, Health risks, Medical cannabis, Regulation and legalization, Therapeutic benefits

INTRODUCTION

Cannabis has been used in medicine for thousands of years, but its modern resurgence in medical applications has been met with significant research interests and regulatory debates. Proponents of medical cannabis support its use for a highly varied range of medical conditions, most notably in the field of pain management and multiple sclerosis.1

The current findings from the population based surveys in Canada and the US add to the evidence that cannabis use is more prevalent and frequent among those who experience mental health conditions.2 Cannabis is a complex plant with over 400 chemical entities of which more than 60 of them are Cannabinoid compounds, some of them with opposing effects; these are delta-9-tetrahydrocannabinol, Cannabidiol, tetrahydro-cannabivarin, endocannabinoids, cannabis, etc.3 Cannabis has been used recreationally for millennia and is the third most commonly used drug after tobacco and alcohol.4 There is one direct source of evidence (delta6-tetrahydrocannabinol (delta 6-THC) in ashes) that cannabis was first used medicinally around 400 AD. In the U.S., cannabis was widely utilized as a patent medicine during the 19th and early 20th centuries, described in the United States Pharmacopoeia for the first time in 1850.5

The use of cannabis has been reported in India for at least a few thousand years; however, it was only in the 1800 that cannabis cultivation and use expanded rapidly in India and worldwide as nonpsychoactive hemp emerged as a valuable cash crop and thus the British rulers of India commissioned the mass cultivation of cannabis, which subsequently increased the rates of cannabis use as well.6 In 1996, California became the first state to permit legal access to and use of botanical cannabis for medical purposes under physician supervision with the enactment of the compassionate use act.5

This review article summarizes the benefits and risks of cannabis use in medicine with a comprehensive format gathering important aspects and evidences of randomized control trials (RCTs). It also includes short term as well as long term side effects along with safety and quality check. It also mentions legal and ethical considerations of medical cannabis.

Figure 1: Components of endocannabinoids system.
Figure 1: Components of endocannabinoids system.
Figure 2: Mechanism of action of endocannabinoid system in response to an excitatory neurotransmitter in the neuronal synapse.
Figure 2: Mechanism of action of endocannabinoid system in response to an excitatory neurotransmitter in the neuronal synapse.
Table 1: Medical uses of cannabis.
Table reproduced from source PDF page 3

DISCUSSION

Mechanism of action

The discovery of its compounds has led to the further discovery of an important neurotransmitter system called the Endocannabinoid System. The main components of Endocannabinoid System are the receptors which are G protein coupled receptors (GPCRs), primarily coupling to inhibitory G proteins. CB1 receptors are exclusively found in brain (basal gangli, limbic system, hippocampus, cerebellum, astrocytes) but are also found in thyroid, uterus, testicular tissue, etc. CB2 receptors are found mostly in immune cells, GI system, peripheral nervous system, etc.3,8,9

Risks and side effects

Cannabis use in medicine raises the possible risks and side effects as large doses can increase the risk of significant mental health issues especially psychosis.22 Cannabinoids can have a significant impact on cardiovascular system, respiratory system, nervous system especially in adolescents which could be a future threat. Side effects of Cannabinoids can be grouped into short term and long-term side effects.

Short term side effects

These primarily include intoxication and abuse of large doses of cannabis and early appearance of symptoms lasting for a few hours to weeks in all age groups. Increased risk of motor-vehicle accidents.22-27 Coronary vasospasm.22,23,28 Cannabis Arteritis.22,23,28 Increased heart rate, Change in Blood Pressure.22,23,25,26 Myocardial Infarction.22,26,27 Stroke.26,29 Cognitive Impairment.5,23,25,26,29 Impairs verbal memory, attention and psychomotor function.5,23,26,29 Euphoria, disorientation, sleepiness, dizziness.25,29 Hallucinations or delusions.25

Long term side effects

These specifically include symptoms that chronically develop by taking small to large doses over a long period of time usually for months to years in all age groups.

Chronicity of neurocognitive alterations especially in adolescents.23-25,29,30 Dependence.23-25,28,29 Chronic bronchitis or COPD, asthma, emphysema.22,25 Smoking cannabis causes increased risk of lung cancer.23-25 Increased risk of infections (immunosuppressants).23 Increased risk of cardiovascular diseases.23-25,28

Impact on mental health

Considerable effects have been noted on impacts on mental health as mentioned in the above table by the use of cannabis ranging from potential benefits to risks and dependence. Despite the constant rise of global prevalence rates, many of the current therapeutic options for mental illnesses are far from being ideal in terms of both efficacy and adverse effects.13 It can be used in many psychiatric disorders but also has side effects like impairment of memory, psychomotor function and neurocognitive alterations.22-24 It can also lead to intoxication, euphoria, hallucinations and thus should be cautiously evaluated in therapeutic settings.

Safety and quality concerns

The uncertainty surrounding safety and efficacy of exogenous cannabinoids is not a product of lack of research, but rather a product of extreme variability in study methodology and quality.23 Also, there is insufficient high quality data regarding the efficacy, dose-dependent curve, drug interactions, expected adverse effects and safety of the commercial available medical cannabis products.31 When evaluating the safety profile of medicinal cannabis products, it is important to consider the relative THC and CBD content, as CBDs have an excellent safety profile; and thus Therapeutic Goods Administration (TGA) recently approved a legal pathway for low dose formulations to be provided over the counter as Schedule 3 pharmacist-only medications for conditions that do not require medical oversight.32

Unlike conventional pharmaceuticals, cannabis products often lack consistency and standardization of doses. Additionally, evidence for long term and enduring cognitive and memory dysfunction along with impact on cardiovascular system and dependence is highly contentious.32 In general, the current evidence suggests that individuals can substantially reduce their risk for adverse health outcomes if they delay the cannabis use until after adolescence, avoid the use of high-potency (THC) cannabis products and high frequency or intensity of its use and refrain from smoking routes of administration.33 High quality cannabis is defined as not causing excessive intoxication or physical harm.34 This also requires stronger regulatory oversight, standardised production practices and more extensive research to ensure that cannabis can be safely and effectively integrated into medical treatments.

Legalization of cannabis use in medicine is taking place rigorously. In 1996, California was the first to legalise and till 2020, 33 states of US and District of Columbia have legalized medical marijuana and 11 states allowed adult recreational use.35 Because specific state laws and regulations may not reflect the current body of evidence, legal and ethical issues of cannabis may at times be a conflict.35

In professional perspective, physicians are expected to prescribe unstandardized agents with no FDA approval, but with potentially unexpected effect and advanced reactions as since medical cannabis dosing and potency is not regulated, there is an unavoidable knowledge gap.31

Ethical concerns36

The benefits of medical use of cannabis may exceed its own risks and whether it should be recommended without the usual protections afforded to patients. Concerns of doctor-patient relationship, as major healthcare systems do not allow physicians to recommend drugs which are not FDA approved. Autonomy is an issue, as patient-clinician discussions about the risks, benefits and alternatives to cannabis should include these items. Risk of harm, as non-maleficence imposes an obligation on clinicians to refrain from doing harm and there are several potential harms associated with cannabis. Additional ethical considerations that become salient to cannabis use that are related to social context and lingering misconceptions.35

CONCLUSION

Advancements in the cannabinoid research would not stop even if there are considerable barriers.7 Research Gaps do exist concerning the effectiveness of cannabidiol or cannabidiol-enriched cannabis in treating the following:10

Oncology, epilepsy, irritable bowel syndrome, spasticity due to paraplegia from spinal cord injury, huntington’s disease, psychiatric disorders, amyotrophic lateral sclerosis, etc. Impact of Phyto cannabinoids as therapy to restore the function of MGBA in TBI patients. Further research for an in-depth investigation into signaling pathways and its activation. Impact of Cannabinoids on adhesion molecules, co-stimulation, and chemotaxis.11 Approach to cannabis as a legitimate therapeutic agent.23 Impact of marijuana in pregnant women.24 Finding relevance in cannabis use associated with fatal motor-vehicle accidents.24

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: Not required

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