Specific Medicinal Uses of Cannabis: Use as an Antiemetic

Many agents used in cancer chemotherapy produce severe nausea and vomiting in most patients. Symptoms can last for hours or days and have a major impact on patient nutrition and electrolyte status, body weight and physical and mental resilience to both the disease and its treatment. The current choice of available anti-emetics is limited and most are only partially effective, which may lead patients to refuse therapy all together, or for clinicians to use chemotherapeutic regimens which are less than optimum. For these reasons, the search for more effective antiemetics continues. Cannabis In the late 1960s and early 1970s, patients receiving various cancer chemotherapy regimes (including mustine, vincristine, prednisone and procarbazine) noted that smoking cannabis from illicit sources, before and during chemotherapy, reduced the incidence of nausea and vomiting to a variable degree. Only since the isolation of THC have formal clinical trials on the safety and efficacy of cannabis derivatives been conducted. As far as crude cannabis is concerned, we have only anecdotal evidence that inhaling its smoke is effective in a variable percentage of patients who vomit, despite supposedly adequate doses of standard antiemetics. There Read more […]

Heimia salicifolia

Description, Distribution, and Uses of Heimia salicifolia Heimia salicifolia, a small shrub of the Lythraceae is the source of biphenylquinolizidine lactones and related alkaloids. Heimia is distributed throughout the tropical and subtropical climates of the American Continent and has been described as reaching 0.5-3 m in height. It has sessile, linear lanceolate leaves that are generally opposite. The yellow flowers are solitary and axillary. The fruit is a capsule filled with small (ca. 0.5 mm diameter) ovoid seeds. H. salicifolia has received several common names. In Mexico it is mostly known as sinicuiche and less frequently as sinicuilche, sinicuil, huachinol, anchinol and xonecuili. In Brazil it is locally known as abre-o-sol, herva da vida and quebra arado and in Argentina as quiebra arado. The Mexican name sinicuiche is of most common use. H. salicifolia has been used as a folk remedy especially in Mexico. It has been employed as a diuretic, laxative, antisyphilitic, emetic, vulnerary, digestive and to treat cases of dysentery, inflammation of the uterus, bronchitis, and other chest ailments. In addition, inhibition of a beverage produced from the fermented plant is said to cause a mild state of intoxication Read more […]

Anxiety Disorders: Supplements With Possible Efficacy

In addition to supplements discussed above, a few other compounds may also have some efficacy in treating symptoms of anxiety. However, since the data that supports the use of the following supplements is extremely limited, clinicians should proceed with caution, and consider the use of the compounds discussed in this section as experimental. St. John’s Wort As described in site, St. John’s Wort (Hypericum perforatum) is an herb that exists in many species throughout the world, and it is widely used as an antidepressant. It is available in a variety of preparations, including capsules, liquid, oils, and raw herb to be brewed as tea. St. John’s Wort contains a plethora of active ingredients, including flavonoids, naphthodianthrones, phloroglucinols, phenolic acids, terpenes, and xanthones. These exert a variety of psychoactive effects, and several of these are described below. Of all herbal supplements, St. John’s Wort is the one that has been researched most extensively and there is strong support for its efficacy in reducing depressive symptoms. The use of St. John’s Wort as an anxiolytic is more recent, but a few studies suggest that is may be effective. Davidson and Connor (2001) reported case studies of patients Read more […]

DOPAMINE RECEPTOR AGONISTS

DOPAMINE RECEPTOR AGONISTS act to stimulate dopamine receptors, and these have a major neurotransmitter role in the CNS. Dopamine is also a precursor in the formation of the catecholamine monoamine neurotransmitter noradrenaline and the hormone adrenaline. The distribution of dopamine in the brain is very non-uniform. There is some in the limbic system, and a large proportion is found in the corpus striatum — a part of the extrapyramidal motor system which is concerned with the coordination of movement. Dopamine-containing nerves are found in three main pathways in the brain. The nigrostriatal pathway contains about 75% Of the dopamine in the brain, and the cell bodies lie in the substantia nigra and the nerves terminate in the corpus striatum. The second important pathway is the mesolimbic pathway, the cell bodies of which lie in the mid-brain and project to parts of the limbic system, particularly the nucleus accumbens. The third, the tubero-infundibular system, consists of short neurons that run from the arcuate nucleus of the hypothalamus to the median eminence and the pituitary gland, the secretions of which they regulate. With respect to disturbances of dopamine neurotransmitter function, the first-mentioned Read more […]

Herb-Drug Interactions: Cannabis

Cannabis sativa L. (Cannabaceae) Synonym(s) and related species Bhang, Dagga, Ganja, Hashish, Indian hemp, Marihuana, Marijuana. Cannabis indica Lam. Constituents Cannabis herb contains a wide range of cannabinoids, which are the major active compounds. The main psychoactive constituent is delta9-tetrahydrocannabinol (THC; dronabinol), and it is the cause of many of the pharmacological effects elicited by the consumption of cannabis. However, other cannabinoids, which do not possess psychoactive properties, such as cannabidiol, cannabinol (a decomposition product of delta9-tetrahydrocannabinol), cannabigerol and cannabichromene, are increasingly being investigated for their pharmacological and therapeutic properties. Cannabinoids are often found in the plant as their acid metabolites, e.g. ll-nor-9-carboxy-delta9-tetrahydrocannabinol, cannabidiol acid and others, especially if the plant has been grown in a cooler climate. These decarboxylate to the parent cannabinoid at high temperatures, such as during smoking. Most medicinal cannabis products have been heat treated to ensure that the cannabinoids are present only in the non-acid form. Use and indications Cannabis has no current established use in herbal Read more […]

CNS DEPRESSANTS

CNS DEPRESSANTS depress the CNS. In practice, very diverse agents can be grouped under this heading and it does not describe any specific type of drug action. Most of the agents that depress neuronal activity in the brain or spinal cord are dealt with under specific headings. The properties of some of these classes will be summarized here. GENERAL ANAESTHETICS are either inhaled or injected agents and produce insensibility, mostly to alleviate pain during surgical procedures (e.g. halothane, thiopentone sodium). HYPNOTICS induce sleep and a wide range of chemical types may be used. The older agents, such as the barbiturates, were often SEDATIVE agents used at a higher dose, but they readily produced dangerous respiratory depression and are now much less commonly used (e.g. amylobarbitone, chloral hydrate, chlormethiazole, triclofos). Increasingly, the drugs of choice are anxiolytic/minor tranquillizers at a somewhat higher dosage (vide infra). Tranquillizers depress the CNS. The need for the term came with the introduction of drugs having rather more subtle effects on mood and behaviour than the barbiturates. However, it soon became necessary to divide the category into minor tranquillizers and major tranquillizers. Read more […]

CARDIAC DEPRESSANTS

CARDIAC DEPRESSANTS are little used in medicine, however, some are used to slow the heartbeat in tachycardias and a number of these are often analogues or derivatives of other drugs with optimized activity for this purpose in the heart (e.g. procainamide, quinidine) — these are dealt with under antiarrhythmic agents. In addition to drugs in these classes, many drugs have the adverse effect of cardiac depression as a side-effect. This is particularly so with LOCAL ANAESTHETICS (e.g. lignocaine, procaine), which is a major reason why they are only used by local application. A number of other drugs, particularly chemotherapeutic agents that have strong reasons for their selection, may be cardiac depressants in some patients at high doses (e.g. doxorubicin, quinine). Many drugs with depressant actions on the CNS are also cardiac depressant in higher doses (e.g. carbamazepine. chlorpromazine, pentobarbitone). Drugs with actions on the autonomic system may have cardiac depressant actions (e.g. bretylium, reserpine) Also, β-adrenoceptor antagonists, whose actions are generally beneficial, can in some conditions and in overdose cause heart block or even cardiac arrest. Cholin-oceptor muscarinic agonists, by definition, Read more […]

Herb-Drug Interactions: Evening primrose oil

Oenothera biennis L. (Onagraceae) Synonym(s) and related species Common evening primrose, King’s cureall, Sun drop, Tree primrose. Oenothera lamarkiana, Onagra biennis (L.) Scop. Pharmacopoeias Evening primrose oil (British Ph 2009, European Ph, 6th ed., 2008 and Supplements 6.1, 6.2, 6.3 and 6.4). Constituents The oil from evening primrose seeds contains the essential fatty acids of the omega-6 series, linoleic acid (about 65 to 85%) and gamolenic acid (gamma-linolenic acid, about 7 to 14%). Other fatty acids include oleic acid, alpha-linolenic acid, palmitic acid and stearic acid. Use and indications Evening primrose oil is used as a food supplement to provide essential fatty acids. It is also used for atopic eczema and mastalgia; however, in the UK licences for two prescription products containing gamolenic acid derived from evening primrose oil were withdrawn in 2002, due to lack of evidence in support of efficacy. Other conditions for which it is used include rheumatoid arthritis, premenstrual syndrome, menopausal symptoms, chronic fatigue syndrome and attention deficit hyperactivity disorder. Evening primrose oil has also been used topically as a cream, for the relief of dry or inflamed skin. Read more […]

ANTIEMETICS

ANTIEMETICS are used to prevent vomiting. They are thus related to antinauseant drugs which are used to reduce or prevent the feeling of nausea that very often precedes the physical process of vomiting (emesis). Commonly, the terms are used synonymously, though it is usually an antinauseant action that is being sought. The type of antinauseant drugs used, and the likelihood of success, depends on the mechanism and origin of the nauseous sensation, and there are a number of ways it can be triggered. Motion sickness (travel sickness) can often be prevented by taking antinauseant drugs before travelling, e.g. the antihistamines meclozine and dimenhydrinate, and the anticholinergic hyoscine. Probably all these drugs act as central MUSCARINIC CHOLINOCEPTOR ANTAGONISTS. Similar drugs may be used to treat nausea and some other symptoms of labyrinthine disease (where the vestibular balance mechanisms of the inner ear are disturbed, e.g. in Meniere’s disease), though other antinauseant drugs may also be necessary, e.g. cinnarizine or phenothiazine derivatives such as chlorpromazine and prochlorperazine. Steroids, such as dexamethasone and methylprednisolone, are effective antiemetics that work by an undefined mechanism. In view Read more […]

ANTICONVULSANTS

ANTICONVULSANTS are drugs used to treat convulsions of various types, for instance, in drug or chemical poisoning, e.g. chlorpromazine, diazepam. However, these anticonvulsants are not necessarily effective or suitable for epilepsy. In practice, the antiepileptic drugs are the more used, especially for prolonged treatment, and these agents have extensive usage in preventing the occurrence of epileptic seizures. The drug of choice depends on the type and severity of the epilepsy. For tonic-clonic seizures (Grand Mai) as part of a syndrome of primary generalized epilepsy the drugs of choice are carbamazepine and phenytoin. For absence seizures (Petit Mai), sodium valproate and ethosuximide. For myoclonic seizures, sodium valproate, clonazepam and ethosuximide. For other types of seizure, such as atypical absence, atonic and tonic seizures (often in childhood), phenytoin, sodium valproate, clonazepam, phenobarbitone, or ethosuximide are valuable. These all appear to work by stabilizing membranes and decreasing excitability, though with differing profiles of activity and mechanisms of action. Phenobarbitone, though a barbiturate, is more of an anticonvulsant than expected from its sedative actions, and it resembles Read more […]