Neurotransmitters Involved with Cannabinoid Action

Cannabis is a complex mixture of cannabinoid molecules (over 61 have been identified) and other chemicals (of which 400 have been identified); with THC as the main active cannabinoid responsible for the psychotropic effects. All these chemicals may have a wide variety of mechanisms of action and that of their metabolites may well be different again. So far, studies have concentrated on THC and a number of synthetic analogues, revealing a number of possible mechanisms of action. The central nervous system (CNS) transmitters that modulate the perceptions of pain include noradrenaline, serotonin (5HT), acetylcholine, GABA, the opioid peptides and the prostaglandins. Reports suggest that the analgesic effects seen with the cannabinoids involve prostaglandins, noradrenaline, 5HT and the opioid peptides, but not GABA or acetylcholine. The involvement of the prostaglandins is complex. The cannabinoids are stimulators of phospholipase A2, promoting the production of prostaglandins, but also inhibitors of cycloxygenase therefore also inhibiting production. The scene is further complicated by the fact that prostaglandins oppose pain centrally but cause pain at peripheral sites (). This may explain why in some tests involving Read more […]

Asteraceae: Drug Interactions, Contraindications, And Precautions

Patient survey data from Canada, the U.S., and Australia show that one in five patients use prescription drugs concurrently with CAM. The inherent polypharmaceutical nature of complementary and alternative medicine increases the risk of adverse events if these complementary and alternative medicine either have pharmacological activity or interfere with drug metabolism. Since confirmed interactions are sporadic and based largely on case reports, advice to avoid certain drug-CAM combinations is based on known pharmacological and in vitro properties. Known Hypersensitivity to Asteraceae Cross-reactive sesquiterpene lactones are present in many, if not all, Asteraceae. Patients with known CAD from one plant may develop similar type IV reactions following contact with others. Affected patients are often advised to avoid contact with all Asteraceae, yet this advice is based on limited knowledge of cross-reactivity between relatively few members of this large family. Some authorities recommend avoiding Asteraceae-derived complementary and alternative medicine if, for example, the patient is known to have IgE-mediated inhalant allergy to ragweed. While a reasonable approach, this ignores a number of important facts: (1) Read more […]

Hypericum perforatum

St John’s wort (Hypericum perforatum) is a native flowering plant of Europe and Asia which produces attractive yellow flowers. According to Kiple and Ornelas (2000) its lemon-scented leaves have been used for thousands of years as human food and have also been used to make a form of tea. Extracts of the flowers and leaves of this plant are now widely taken in the belief that they are mood enhancing and have beneficial effects in the treatment of clinical depression. In Germany hypericum extracts are widely prescribed by physicians for the treatment of clinical depression and it is the best selling antidepressant there. What is depression? Clinical depression is a common, painful and disabling condition which is more severe than the normal downward fluctuations in mood that we all regularly experience. The American Psychiatric Association lists the following symptoms for depression: • Depressed mood • Loss of interest in and lack of pleasure derived from activities that the patient usually finds pleasurable • Disturbed sleep patterns • Abnormal activity patterns, either agitation or being uncharacteristically inactive • Loss of drive and energy, loss of sex drive and reduced appetite To Read more […]

Treatment Of Depression

Depression ranks as one of the most widespread mental health problems in the world. Besides causing significant morbidity and mortality (through suicide), depression also contributes to or is associated with several other serious problems. Depression may contribute to atherosclerosis, perhaps by impairing glucose tolerance, and depression has been repeatedly linked to depressed immune function. In fact, over half of people with chronic or severe illnesses may suffer from depression. Depression can strike at any age, but depression in the elderly is a particularly significant problem. The surgeon general of the United States recently noted that suicide rates increase with age and that nearly 5 million of the 32 million Americans over 65 suffer from some form of depression. Natural medicine offers many options for helping cope despite the enormity of the problem of depression at any age. Today, allopathic antidepressant drugs are all too often prescribed and dispensed without a second thought as a treatment for depression. The decision to institute or maintain patients on these drugs should be made much more cautiously. The profitable new antidepressant drugs (selective serotonin-reuptake inhibitors [SSRIs] and atypical Read more […]

Cerebrovascular Insufficiency And Depression

Atherosclerosis of the vasculature feeding the brain can lead to a condition known as cerebrovascular insufficiency. This chronic low-grade ischemia can impair memory or otherwise mimic dementia. It can also produce a syndrome resembling depression. This syndrome is surprisingly little discussed in the United States but is much more widely recognized in Europe. The treatment is obviously the same as for atherosclerosis anywhere in the body — elimination of the underlying dietary and lifestyle causes (especially sedentariness) and addition of supportive nutrients and practices (like meditation). Ginkgo biloba (ginkgo) leaf extracts have been very rigorously shown to help alleviate cerebrovascular insufficiency symptoms. This is almost certainly due to ginkgo’s ability to reduce the underlying atherosclerosis and improve neuron function despite ischemia. It also seems to stimulate blood flow to the brain, perhaps by acting on blood vessels. The usual dose of ginkgo standardized extract is 80-160 mg two or three times per day. It should be used attentively in patients taking anticoagulants as the combination occasionally but rarely may have a synergistic effect and cause bleeding. Gingko has also been shown to Read more […]

Herbs For Behavioral Conditions

Most behavioral conditions in small animals arise from stress and anxiety. These include aggression, inappropriate urination, lick granuloma, separation anxiety, and storm and other phobias. Herbal medicines provide a number of interesting alternatives to conventional veterinary mood-modifying drugs. The approach depends upon the nature of the behavioral disturbance and the severity and duration of the condition. Other perpetuating factors and health issues such as pain or endocrine disturbances, which can contribute to aggression and anxiety, must be considered. Nervines are the traditional class of herbs employed for emotional conditions in humans, and they have applications in veterinary medicine, too. Nervines can be further classified. Nervine relaxants have anxiolytic, sedating, or hypnotic activity. They include herbs such as Valerian, Hops, Lavender, Lemon balm, and Passion flower, and may be prescribed for anxiety, hyperactivity, restlessness, and irritability. Nervine stimulants are perhaps the least used group in veterinary medicine, but they may be beneficial for a depressed or hypoactive nervous system. They may be used extensively by veterinary staff in the form of tea and coffee. Others, such as Kola 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 […]

Bed Wetting

Bed wetting that occurs in a child older than 4 or 5 years who has already developed bladder control is frequently related to stress. It could be jealousy of a new baby, anxiety about moving house, changing school, trouble with schoolwork, teachers, peers, upset over family discord or anything else that causes stress, over-excitement, insecurity or unhappiness. A child who wets the bed will need plenty of reassurance from parents rather than reprimanding for something they cannot help and probably find humiliating. Fear of others outside the family being aware of the problem and of the social isolation this could mean becomes a stress in itself, which can exacerbate the problem. If a child has never developed proper bladder control, it may be that nerves and muscles governing bladder function are not yet mature enough. Once a child is over 4 years and still wetting the bed regularly there may be underlying causes that require addressing. These include structural abnormality, diabetes, chronic urinary infection, dietary deficiency (particularly of calcium and magnesium), overuse of refined foods and sugar, over-sensitivity to food additives or chemicals in drinking water or food allergy. Some children tend to wet Read more […]

Herb-Drug Interactions: Melatonin

N-(2-(5-Methoxyindol-3-yl)ethyl)acetamide Types, sources and related compounds N- Acetyl-5-methoxytryptamine. Use and indications Melatonin is a hormone that is produced in the pineal gland of the brain and influences the circadian rhythm. Supplements are therefore principally used for treating sleep disturbances and disorders such as jet lag, insomnia, sleep walking, and shift-work sleep disorder. It is also believed to have anticancer and antihypertensive properties, and has been used to treat cluster headaches. Melatonin has also been detected in a large number of plant species, including those used as foods. Concentrations detected have been very variable, the reasons for which are currently uncertain. In addition, the importance of dietary melatonin is unclear. Pharmacokinetics When an oral melatonin supplement 3mg was given to 17 healthy subjects the AUC and maximum serum levels of melatonin were about 18-fold and 100-fold greater, respectively, than overnight endogenous melatonin secretion, although there was a wide variation between individuals.The oral bioavailability was approximately 15% after oral doses of 2 or 4mg, possibly due to significant first-pass metabolism. The half-life has been found Read more […]

ANTIDEPRESSANTS

ANTIDEPRESSANTS are used to relieve the symptoms of depressive illness, an affective disorder. There are three main groups of drugs used for the purpose. All interfere with the function of monoamine neurotransmitters, and the considerable delay before antidepressants become effective is taken as evidence of a down-regulation of noradrenergic or serotonergic systems (rather than the opposite, as advanced in Schildkraut’s original amine theory of depression). Tricyclic antidepressants are the oldest group (named after the chemical structure of the original members) .e.g. imipramine. They act principally as CNS monoamine (re-) UPTAKE INHIBITORS. Although far from ideal, this is still the most-used antidepressant group. Chemically, they have gone through transformations from the dibenzazepines (e.g. imipramine, desipramine), to dibenzcycloheptenes (e.g. amitriptyline, nortryptyline), dibenzoxepines (e.g. doxepin) and some recent members are not strictly tricyclics. They are effective in alleviating a number of depressive symptoms, though they have troublesome anticholinergic and other side-effects. Most drugs of this class also have sedative properties, which is more pronounced in some, especially amitriptyline, which Read more […]