Examining Medical Uses Of Marijuana Biology Essay

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The purpose of this paper is to examine medical uses of marijuana as an alternative therapy for severe disease states and illnesses. According to Grinspoon the pharmacological compound of marijuana and its chemical make-up, are analyzed in order to determine the potent components that are said to make this drug work for clinical uses. Reports are made about the wide ranges of medical and therapeutic uses of the drug with severe states of diseases and illnesses such as Aids, Glaucoma, Cancer, and Neurological disorders. Various theories and facts about marijuana as a therapeutic aid are sought in order to determine its contribution to various disease processes.

Keywords: Medical Marijuana, Aids, Glaucoma, Cancer, Neurological disorders, disease, therapeutic

Medical Marijuana

Thousands of severely ill people in the United States seek additional or alternative therapies in order to make particular symptoms subside or vanish. Many people seek these measures when traditional therapies do not work, and or when they need more than the popular prescription medicines to make them feel better. An example of an alternative therapy that some people use is Medical Marijuana. According to Kumar, Chambers, and Pertwee this illegal substance has particular therapeutic effects that are said to work better than other drugs. The purpose of the paper is to describe the pharmacology, adverse effects, and various therapeutic uses of marijuana, as well as legal issues that cover the controversy.

Cannabis is a popular word that originates from Cannabis sativa, which is the name of the marijuana plant. Marijuana is one of the most popular drugs used in the United States. More than 50 percent of Americans have tried of will try marijuana at some point in their life (Hubbard, Franco, & Onaivi, 1999). Cannabis was first introduced to Western medicine in 1839 by W.B. O'Shaughnessy at the Medical College of Calcutta, were he observed the drug's use for effectiveness as an analgesic, anticonvulsant agent, and muscle relaxant (Grinspoon, 2001). Other researchers hypothesize that medical marijuana use data back further to 400 AD for treatment of relieving labor pain, and increasing uterine contractions in pregnant women (Ed-derfoufi, Merzouki, & Mesa, 2000). Marijuana is made from dried leaves and flowers of the marijuana plant. The potency of the drug depends on the method the drug (Hubbard et al., 1999). This is why the same quantity of marijuana can sometimes produce different effects. Ganja, said to be three times more potent than marijuana and hashish, is reported to be five to eight more potent than all other forms (Hubbard, et al., 1999).

The Cannabis sativa plant contains more than 426 chemical products in its genetic make-up that consist of alkaloid derivatives of spermidine, sterols, terpenes, and flavanoid glucosides (Cabral & Pettit, 1998). Most of the cannabinoids is found on the flower-like tops of the marijuana plant. There are more than 60 cannabinoid compounds, which include cannabidiol, cannabinol, and the primary psychoactive component delt-9-tetrahydrocannabinol also known as THC. Majority of the other cannabis are either inactive, or have decreased potential for action because they are too weak (Solowij, 1998). THC is the main cannabinoid that is found to be active in marijuana (Hubbard et al., 1999). It has a higher molecular weight that doesn't contain any nitrogen in its chemical structure and acts as a "false hormone" that has the ability to interfere with the action of natural hormones in the body (Joy et al., 1999).

According to Hubbard et al. (1999) the pharmacokinetics of marijuana consists of it stimulating the dopamine pathway from the ventral tegmental area to the nucleus accumbens, which is believed to be a reward system of the brain. There are two different endogenous cannabis receptors in the brain that are identified as CB1 and CB2 (Hubbard et al., 1999). "CB1 receptors are distributed widely throughout the central nervous system (CNS) and the peripheral nervous system (PNS). They are present in the greatest concentration around the hippocampus, cortex, olfactory areas, basal ganglia, cerebellum, and spinal cord" (Kumar, Chambers, & Pertwee, 2001, P.1059). Kumar et al. (2001) reports that this pattern accounts for the effects of cannabinoids on memory, emotion, cognition, and movement. CB2 receptors are found in peripheral areas and are closely associated with cells in the immune system, such as the spleen and macrophages (Kumar et al., 2001). The brain stem does not have that many cannabinoid receptors, which gives reason to why marijuana does not suppress respiration in high doses and why it has a high therapeutic index (Hubbard et al., 1999). "THC is not a naturally occurring substance within the brain, the existence of a brain cannabinoid receptor implied the existence of an endogenous cannabinoid like substance" (Solowij, 1998, p.17). A fat-soluable molecule in the brain identified as Anandamide, is a substance similar to THC that "mimics" the action of cannabinoids (Solowij, 1998). This molecule acts as a neurotransmitter for cannabinoid receptors, but has less potency and a shorter duration of pharmacological activity than THC (Solowij, 1998).

The most popular route of administration for cannabinoids is through smoke, but they can also be eaten, drunk as tea, or through intravenous injection, which is not a common practice (Hubbard et al., 1999). When smoked, marijuana can be "hand rolled as a joint," or smoked out of a pipe (Solowij, 1998). Tobacco can also be added to make the drug burn slower and last longer. Oral ingestion, usually involves marijuana that is baked in foods and eaten, or taken in the form of a gelatin capsule that has been prepared for medical use, such as Marinol ® (Benson, Watson, & Joy, 1999; Solowij, 1998). Marionol ®, also known as dronabinol, is the only cannabinoid based drug on the market that is approved by the Food and Drug Administration for nausea and vomiting associated with chemotherapy (Benson et al., 1999). "In India a popular method of ingestion is in the form of tea…known as "bhang." The high is of lesser intensity but the duration of intoxication is longer by several hours" (Solowij., 1998, p.19). Intravenous administration of marijuana is rare, but done on occasion to study the pharmacokinetics (Solowij, 1998).

According to Solowij (1998), the dosage of a typical joint contains between 0.3 and 1.0 grams of cannabis plant, capsule forms range from 10 to 25 milligrams, and the bioavailability of THC from marijuana ranges from 5% to 24%. Marmor (1998) identified:

Psychopharmacologic effects peak at 30 to 60 minutes. After the oral ingestion of THC or marijuana the plasma concentrations of THC rise slower over 1 to 3 hours; the onset is slower, and subjective effects lasts 5 to 12 hours without a clear peak (p. 541).

An advantage of smoking marijuana rather than oral consumption is that the onset is rapid and the effects are short, allowing patients to self-titrate doses (Marmor, 1998). Oral consumption of THC is absorbed slow and enters the bloodstream one to three hours after administration (Solowij, 1998). Kumar et al. (2001) reports that some of the THC is degraded in the liver by first-pass metabolism and that cannabinoids are able to cross the placenta and enter breast milk. "THC's half life is seven days, but because the organs with high lipid concentrations excrete the THC slowly it takes approximately one month to eliminate all traces of THC from the body" (American Family Physician [AFP], 1982, p.268). Some acute effects associated with marijuana use include euphoria and relaxation, perceptual alteration, time distortion and the intensification of normal sensory experiences such as eating, sexual arousal, heightened sensations and socializations with other users (Hubbard et al., 1999; Kumar et al., 2001).