Thursday, November 21, 2013
Burgess reagent
The Burgess reagent or methyl N-(triethylammoniumsulfonyl)carbamate was developed in the laboratory of Edward M. Burgess at Georgia Tech. It is a mild and selective dehydrating reagent often used in organic chemistry. It is used to convert secondary and tertiary alcohol with an adjacent proton into alkenes. Primary alcohols do not work well. The reagent is soluble in common organic solvents and alcohol dehydration takes place with syn elimination. The Burgess reagent is a carbamate and a so-called inner salt. A general mechanism is shown below.
About Tadanafil
Tadalafil is a PDE5 inhibitor, currently marketed in pill form for treating erectile dysfunction (ED) under the name Cialis; and under the name Adcirca for the treatment of pulmonary arterial hypertension.
Tadalafil is also manufactured and sold under the name of Tadacip by the Indian pharmaceutical company Cipla in doses of 10 mg and 20 mg.
Since PDE5 inhibitors such as Tadalafil may cause transiently low blood pressure (hypotension), organic nitrates should not be taken for at least 48 hours after taking the last dose of tadalafil. Using organic nitrites (such as the sex drug amyl nitrite) within this timeframe may increase the risk of life-threatening hypotension.
Since people who have taken tadalafil within the past 48 hours cannot take organic nitrates to relieve angina (such as glyceryl trinitrate spray), these patients should seek immediate medical attention if they experience anginal chest pain.[8] In the event of a medical emergency, paramedics and medical personnel should be notified of any recent doses of tadalafil.
Tadalafil is metabolized predominantly by the hepatic CYP3A4 enzyme system. The presence of other drugs which induce this system can shorten tadalafil half-life and reduce serum levels, and hence efficacy, of the drug.
Tadalafil is also manufactured and sold under the name of Tadacip by the Indian pharmaceutical company Cipla in doses of 10 mg and 20 mg.
Since PDE5 inhibitors such as Tadalafil may cause transiently low blood pressure (hypotension), organic nitrates should not be taken for at least 48 hours after taking the last dose of tadalafil. Using organic nitrites (such as the sex drug amyl nitrite) within this timeframe may increase the risk of life-threatening hypotension.
Since people who have taken tadalafil within the past 48 hours cannot take organic nitrates to relieve angina (such as glyceryl trinitrate spray), these patients should seek immediate medical attention if they experience anginal chest pain.[8] In the event of a medical emergency, paramedics and medical personnel should be notified of any recent doses of tadalafil.
Tadalafil is metabolized predominantly by the hepatic CYP3A4 enzyme system. The presence of other drugs which induce this system can shorten tadalafil half-life and reduce serum levels, and hence efficacy, of the drug.
Wednesday, November 20, 2013
About Verapamil
Verapamil is an L-type calcium channel blocker of the Phenylalkylamine class. It has been used in the treatment of hypertension, angina pectoris, cardiac arrhythmia, and most recently, cluster headaches.It is also an effective preventive medication for migraine. Verapamil has also been used as a vasodilator during cryopreservation of blood vessels.
Verapamil's mechanism in all cases is to block voltage-dependent calcium channels.
In cardiac pharmacology, calcium channel blockers are considered class IV antiarrhythmic agents. Since calcium channels are especially concentrated in the sinoatrial and atrio-ventricular nodes, these agents can be used to decrease impulse conduction through the AV node, thus protecting the ventricles from atrial tachyarrhythmias.
Calcium channels are also present in the smooth muscle that lines blood vessels. By relaxing the tone of this smooth muscle, calcium-channel blockers dilate the blood vessels. This has led to their use in treating hypertension and angina pectoris.
The pain of angina is caused by a deficit in oxygen supply to the heart. Calcium channel blockers like Verapamil will dilate blood vessels, which increases the supply of blood and oxygen to the heart. This controls chest pain, but only when used regularly. It does not stop chest pain once it starts. A more powerful vasodilator such as glyceryl trinitrate may be needed to control pain once it starts.
Verapamil is also used intra-arterially to treat cerebral vasospasm. Verapamil has been used to treat cluster headaches, but it can also cause headaches as a side effect.
Verapamil's mechanism in all cases is to block voltage-dependent calcium channels.
In cardiac pharmacology, calcium channel blockers are considered class IV antiarrhythmic agents. Since calcium channels are especially concentrated in the sinoatrial and atrio-ventricular nodes, these agents can be used to decrease impulse conduction through the AV node, thus protecting the ventricles from atrial tachyarrhythmias.
Calcium channels are also present in the smooth muscle that lines blood vessels. By relaxing the tone of this smooth muscle, calcium-channel blockers dilate the blood vessels. This has led to their use in treating hypertension and angina pectoris.
The pain of angina is caused by a deficit in oxygen supply to the heart. Calcium channel blockers like Verapamil will dilate blood vessels, which increases the supply of blood and oxygen to the heart. This controls chest pain, but only when used regularly. It does not stop chest pain once it starts. A more powerful vasodilator such as glyceryl trinitrate may be needed to control pain once it starts.
Verapamil is also used intra-arterially to treat cerebral vasospasm. Verapamil has been used to treat cluster headaches, but it can also cause headaches as a side effect.
Mepivacaine hydrochloride
Mepivacaine is a local anesthetic[1] of the amide type. Mepivacaine has a reasonably rapid onset (more rapid than that of procaine) and medium duration of action (shorter than that of procaine) and is marketed under various trade names including Carbocaine and Polocaine Mepivacaine hydrochloride is rapidly metabolized, with only a small percentage of the anesthetic (5 to 10 percent) being excreted unchanged in the urine. Mepivacaine because of its amide structure, is not detoxified by the circulating plasma esterases. The liver is the principal site of metabolism, with over 50 percent of the administered dose being excreted into the bile as metabolites. Most of the metabolized mepivacaine is probably resorbed in the intestine and then excreted into the urine since only a small percentage is found in the feces. The principal route of excretion is via the kidney. Most of the anesthetic and its metabolites are eliminated within 30 hours. It has been shown that hydroxylation and N-demethylation, which are detoxification reactions, play important roles in the metabolism of the anesthetic. Three metabolites of mepivacaine have been identified from adult humans: two phenols, which are excreted almost exclusively as their glucuronide conjugates, and the N-demethylated compound (2´,6´ - pipecoloxylidide).
The onset of action is rapid (30 to 120 seconds in the upper jaw; 1 to 4 minutes in the lower jaw) and mepivacaine hydrochloride 3% injection without vasoconstrictor will ordinarily provide operating anesthesia of 20 minutes in the upper jaw and 40 minutes in the lower jaw.
Mepivacaine hydrochloride does not ordinarily produce irritation or tissue damage.
Mepivacaine hydrochloride injection, USP, 3% is indicated for production of local anesthesia for dental procedures by infiltration or nerve block in adults and pediatric patients.
Tuesday, November 19, 2013
Phencyclidine hydrochloride
Phencyclidine hydrochloride is a drug used as an anesthetic by veterinarians; illicitly taken (originally in the form of powder or `dust') for its effects as a hallucinogen.
Phencyclidine commonly initialized as PCP and known colloquially as angel dust, KJ (kristal joint), illy, or wet, is a recreational dissociative drug. Formerly used as an anesthetic agent, PCP exhibits hallucinogenic effects.
phencyclidine can cause a kind of brain damage called Olney's lesions in rats. Studies conducted on rats showed that high doses of the NMDA receptor antagonist dizocilpine caused reversible vacuoles to form in certain regions of the rats' brains. All studies of Olney's lesions have only been performed on non-human animals and may not apply to humans. One unpublished study by Frank Sharp reportedly showed no damage by the NDMA antagonist, ketamine, a similar drug, far beyond recreational doses, but due to the study never having been published, its validity is highly controversial.
Phencyclidine commonly initialized as PCP and known colloquially as angel dust, KJ (kristal joint), illy, or wet, is a recreational dissociative drug. Formerly used as an anesthetic agent, PCP exhibits hallucinogenic effects.
phencyclidine can cause a kind of brain damage called Olney's lesions in rats. Studies conducted on rats showed that high doses of the NMDA receptor antagonist dizocilpine caused reversible vacuoles to form in certain regions of the rats' brains. All studies of Olney's lesions have only been performed on non-human animals and may not apply to humans. One unpublished study by Frank Sharp reportedly showed no damage by the NDMA antagonist, ketamine, a similar drug, far beyond recreational doses, but due to the study never having been published, its validity is highly controversial.
Mepivacaine hydrochloride
Mepivacaine hydrochloride is rapidly metabolized, with only a small percentage of the anesthetic (5 to 10 percent) being excreted unchanged in the urine. Mepivacaine because of its amide structure, is not detoxified by the circulating plasma esterases. The liver is the principal site of metabolism, with over 50 percent of the administered dose being excreted into the bile as metabolites. Most of the metabolized mepivacaine is probably resorbed in the intestine and then excreted into the urine since only a small percentage is found in the feces. The principal route of excretion is via the kidney. Most of the anesthetic and its metabolites are eliminated within 30 hours. It has been shown that hydroxylation and N-demethylation, which are detoxification reactions, play important roles in the metabolism of the anesthetic. Three metabolites of mepivacaine have been identified from adult humans: two phenols, which are excreted almost exclusively as their glucuronide conjugates, and the N-demethylated compound (2´,6´ - pipecoloxylidide).
The onset of action is rapid (30 to 120 seconds in the upper jaw; 1 to 4 minutes in the lower jaw) and mepivacaine hydrochloride 3% injection without vasoconstrictor will ordinarily provide operating anesthesia of 20 minutes in the upper jaw and 40 minutes in the lower jaw.
Monday, November 18, 2013
About Icaridin
Icaridin, also known as picaridine, KBR 3023, under the INCI name hydroxyethyl isobutyl piperidine carboxylate, and the trade names Bayrepel and Saltidin, is an insect repellent. It has broad efficacy against different insects and is almost colorless and odorless.It has been reported to be as effective as DEET without the irritation associated with DEET.
Icaridin has been reported to be as effective as DEET without the irritation associated with DEET.According to the WHO, icaridin “demonstrates excellent repellent properties comparable to, and often superior to, those of the standard DEET.” In the United States, the Centers for Disease Control and Prevention recommends using repellents based on icaridin, DEET, or oil of lemon eucalyptus for effective protection against mosquitoes that carry the West Nile virus, Eastern Equine Encephalitis and other illnesses.
Icaridin has been reported to be as effective as DEET without the irritation associated with DEET.According to the WHO, icaridin “demonstrates excellent repellent properties comparable to, and often superior to, those of the standard DEET.” In the United States, the Centers for Disease Control and Prevention recommends using repellents based on icaridin, DEET, or oil of lemon eucalyptus for effective protection against mosquitoes that carry the West Nile virus, Eastern Equine Encephalitis and other illnesses.
Subscribe to:
Posts (Atom)