Entries Tagged 'Drug library' ↓

Oseltamivir(Tamiflu) has been recommended by WHO for the treatment of H1N1 and its complications. Deaths due to Swine flu are on the rise and the pandemic is yet to be brought under control. It is at this juncture that a new study has come out with results questioning the efficacy of the drug in treating the complications of H1N1 flu.

The review was done by BMJ and Channel 4 News in Great Britain.The review found that Oseltamivir has no added benefit in preventing complications of H1N1.No evidence exists that the widely used influenza drug Tamiflu prevents pneumonia or other complications in otherwise healthy patients who come down with the flu.Claims about the effectiveness of the antiviral drug against flu-related complications have influenced governments worldwide to stockpile Tamiflu (oseltamivir) as part of their preparations for a global pandemic, the review authors said.

Based on the data available to them, the authors of the new review concluded they have “no confidence in claims that Tamiflu reduces the risk of complications of influenza in otherwise healthy adults,” and said the drug should not be used in routine control of seasonal flu.

The World Health Organization said Tuesday that data from countries around the world show that when given early, Tamiflu can reduce the severity of swine flu symptoms. Still, the agency recommends the drug be saved for people at risk of complications, such as pregnant women, the elderly, children, and those with chronic health problems, the Associated Press reported.

“This will not change our (Tamiflu) guidelines,” said Charles Penn, a WHO antivirals expert.

Source:Medlineplus

I started taking Oseltamivir as a prophylaxis against swine flu from 31st of August. My plan was to stop the drug by 9th of September as recommended in the WHO site. As I was nearing completion of my drug course, I got exposed to another case of H1N1. The story goes like this

Since clear case definition is not possible in case of H1N1, most of the cases are categorized and isolated. Severe fever and respiratory distress in children has to be suspected to be H1N1 even if no clear history of contact with H1N1 is available.

The child to whom I was exposed was a girl, who had no history of contact or travel abroad.But the troat swab taken from the child came out strongly positive. Even though I wore a mask during my discussion with the parents and the child, I was adviced to take Oseltamivir. Since I was already taking Oseltamivir, I had to start day 1 from day 10. So now my course of Oseltamivir is extended up to Sept 19.

Adverse effects

I had mild head ache and gastric irritation on taking Oseltamivir.My headache was relieved on drinking water(psychological). Some clinical trials show that, there is increased chances of depression and self harm. I had mild depression at the start of medicine, which soon disappeared.

[nausea, vomiting, diarrhea, abdominal pain, and headache. Rare ADRs include: hepatitis and elevated liver enzymes, rash, allergic reactions including anaphylaxis, and Stevens-Johnson syndrome.Various other ADRs have been reported in postmarketing surveillance including: toxic epidermal necrolysis, cardiac arrhythmia, seizure, confusion, aggravation of diabetes, and haemorrhagic colitis.]

Statins are drugs which help in reducing the cholesterol level by blocking the enzyme, HMG CoA Reductace, which is an important component in lipid metabolism.Statins are prescribed in all patients attending hospital with acute coronary syndromes and are given to people who are at high risk for coronary events.

Statins reduce significantly the incidence of coronary events,  being the most efficient hypolipidemic compounds that have

reduced the rate of mortality in coronary patients.

Decrease in LDL cholesterol>>>>antiatherosclerotic effects>>>>Prevent acute coronary syndromes.

Statins act by inhibiting HMG-CoA reductase, which is vital in Cholesterol synthesis. They can exert antiatherosclerotic effects independently of their hypolipidemic action.

Other Advantages

Mevalonate, the product of HMG CoA reductase reaction, is the precursor not

only for cholesterol, but also for many other nonsteroidal

isoprenoidic compounds, inhibition of this

key enzyme may result in pleiotropic effects.

Actions of Statins

Cholesterol Biosynthesis

• Inhibition of cholesterol biosynthesis,
• increased uptake and degradation of low density lipoproteins (LDL),
• inhibition of the secretion of lipoproteins,
• inhibition of LDL oxidation,
• inhibition of the scavenger receptorsexpression

In preventing acute coronary syndromes

• The plaque instability, manifestedas an ulceration of the fibrous cap, the rupture of the

  plaque and internal hemorrhage, are characteristics

  of the plaques with numerous lipid deposits and

  macrophages in the cap

• Statins promoste plaque stability
• statins (fluvastatin, simvastatin) can inhibit t he gelatinolytic activity ofmetalloproteases, as well as their secretion by

  human macrophages in culture.

Others

• statins interfere with events involved in bone formation and impede tumor cell growth.
• Reduction of the accumulation of esterifiedcholesterol into macrophages
• Increase of endothelialNO synthetase,
• reduction of the inflammatoryprocess,
• Increased stability of the atherosclerotic plaques,
• Restoration of platelets activity and of the coagulation process
• Human subjects treated with statins have shown a reduction in the number of bone fractures

How statins are Obtained

Some of the statins are obtained after fungal

fermentation: lovastatin , pravastatin

and simvastatin others

by synthesis: fluvastatin , atorvastatin

, and cerivastatin.

Five statins are, at this moment, in

clinical use: lovastatin, simvastatin, pravastatin,

atorvastatin and fluvastatin.

Adverse effects of statin therapy

The most important adverse effects are liver and muscle

involvement. Myopathy can occur if

cytochrom P450 or other inhibitors of statins

metabolism are co-administered with statins,

Azole antifungals

Fibrates and niacin enhance myopathy risk

Other risk factors are: liver

damage, renal insufficiency, hypothyroidism.