Cycloserine is an anti-tuberculosis drug obtained synthetically, a broad-spectrum antibiotic that has a bacteriostatic or bactericidal effect, depending on its concentration at the site of inflammation and the sensitivity of microorganisms to it. Cycloserine was isolated from cultures of Streptomyces orchidaceus, S.garyphalus and S.lavendulus. Scientists first began to consider this drug as a possible tool to combat tuberculosis in 1955, although at that time the drug was considered dangerous and highly toxic.
Today, cycloserine is considered as a reserve anti-tuberculosis drug. It is recommended for patients with chronic forms of tuberculosis in whom Mycobacterium tuberculosis has become resistant to the main drugs. In addition, some pulmonologists use cycloserine in combination with basic anti-TB drugs to minimize the likelihood of Mycobacterium tuberculosis developing antibiotic resistance.
Cycloserine – Mechanism of Action
The mechanism of action of cycloserine is that this medicine disrupts the synthesis of the cell wall of sensitive strains of gram-positive and gram-negative bacteria and Mycobacterium tuberculosis. In this case, the drug acts as a competitive antagonist of D-alanine; it suppresses the activity of enzymes responsible for cell wall synthesis. Among the microorganisms against which cycloserine is active are the following: Rickettsia spp. and Treponema spp.
However, the highest effectiveness of cycloserine is observed in relation to the causative agent of tuberculosis. Thus, the minimum concentration of the drug at which it inhibits the growth of tuberculosis bacteria is 3-25 mg/l in liquid and 10-25 mg/l in solid nutrient medium. At the same time, in relation to Rickettsia spp. and Treponema spp. cycloserine is effective only in concentrations above 10 and up to 100 mg/l.
Cycloserine is used in the treatment of active pulmonary tuberculosis, as well as extrapulmonary tuberculosis, including renal tuberculosis. It makes sense to prescribe the medicine if the pathogens are sensitive to cycloserine and treatment with the main anti-tuberculosis drugs, such as streptomycin, ioniazid, rifampicin and ethambutol, is inadequate. Cycloserine is often used in combination with other effective chemotherapy drugs, which helps reduce the likelihood of the development of resistance to the tuberculosis pathogen.
In addition, cycloserine is used in the treatment of acute urinary tract infections caused by susceptible strains of gram-positive and gram-negative bacteria, especially Enterobacter spp. and E. coli. However, resorting to this antibiotic in such cases makes sense only if traditional therapy is ineffective and the microorganism is proven sensitive to cycloserine.
Cycloserine Side Effects
As is the case with most other anti-tuberculosis antibiotics, taking cycloserine is fraught with the development of a number of unpleasant and hazardous side effects, while most of the reactions that occur when using cycloserine are associated with its effect on the nervous system or are the appearance of hypersensitivity. The greatest number of complications develop from the nervous system, especially when taking dosages of more than 500 mg per day.
Cycloserine can cause headache, dizziness, insomnia or drowsiness, nightmares, anxiety, irritability, decreased memory and concentration, arrest, peripheral neuritis, demand, euphoria, depression, suicidal tendencies, psychosis, epileptic seizures, aggression, general behavioral changes and even coma.
From the cardiovascular system, an exacerbation of chronic heart failure may occur.
Allergic reactions include skin rash, megoloblastic anemia and increased levels of liver aminotransferases, nausea, heartburn and diarrhea. The latter is particularly common in elderly patients with pre-existing liver disease.
Acute cycloserine toxicity may occur when more than 1 g is ingested by an adult patient. Chronic toxicity of cycloserine is dose dependent and may occur with daily dosing of more than 500 mg. In patients with renal impairment, cycloserine accumulation occurs and toxicity may occur if the dosage regimen is not adjusted. Cycloserine is contraindicated in patients with severe renal impairment.
Cycloserine is produced in the form of tablets or capsules with a dosage of 125 mg, 250 mg or 500 mg. You can purchase cycloserine both in regular pharmacies and online. It should be remembered that self-medication of tuberculosis is unacceptable, and therefore the requirements of pharmacies for presenting a prescription for this medicine must be strictly observed. Even if it is possible to buy cycloserine without a doctor’s prescription, it is advisable not to do this, since treatment is carried out under the supervision of a specialist, and the sensitivity of Mycobacterium tuberculosis to cycloserine should be tested regularly. Otherwise, treatment will only have the opposite effect, strengthening the resistance of bacteria and reducing the range of those drugs that still act on the causative agent of tuberculosis.
At the same time, we should not forget that purchasing cyclaserine online has a number of significant advantages compared to purchasing it in regular pharmacies. First of all, there is a huge selection of generics of this drug. Since this drug is used in the fight against one of the most common diseases in the world, it is produced by almost all major pharmaceutical companies, and who the original patent holder was has already fallen out of human memory.
Prices for cycloserine vary widely. The cost of a tablet averages from 2 to 4 dollars per dosage of 250 mg, which, if taken daily, amounts to quite a considerable amount. A month of taking cycloserine costs patients an average of $75. However, the presence of significantly cheaper generics on the pharmaceutical market makes it possible to save on treatment. You can find deals like a two-month supply of 250 mg tablets for only $4.50 or so, which isn’t even the lowest price. Such offers can usually be found in national Indian and international online pharmacies. They can afford to sell medicines at such low prices due to large sales volumes and the fact that Indian pharmaceuticals are positioned as accessible to people with any income.
If the patient does not want to wait a long time for medicine when ordering from abroad, he can use discount coupons and purchase the medicine at a local offline or online pharmacy. A coupon is a discount card you can print or save to your phone that can save you up to 80% on the cost of prescription drugs. Typically, coupons are posted on special websites, some of which may require you to register, complete a questionnaire, or provide a prescription for a drug.
Cycloserine 250 mg Tablet
250 mg is the most common dosage of cycloserine, which is due to the convenience of calculating the dosage recommended by the doctor, based on dividing such a tablet into two parts and adding half to the whole tablet. A dosage of 500 mg is often quite poorly tolerated by patients, so they are prescribed 375 mg, that is, one and a half tablets. It is important to remember that, regardless of the level of cycloserine in the blood, the maximum daily dosage of cycloserine should not exceed 1 g.