Gemistar Uses, Dosage, Side Effects and more

Gemistar is a fluoroquinolone antibiotic. It is bactericidal with minimum bactericidal concentrations. Gemistar acts by inhibiting DNA synthesis through inhibition of the bacterial type II topoisomerases, DNA gyrase, and/or topoisomerase IV (TOPO IV) which are both essential for bacterial growth.

Gemistar is rapidly absorbed after oral administration. It is widely distributed throughout the body. Studies in healthy subjects showed that gemifloxacin is distributed rapidly into target tissues and body fluids such as the lung (epithelial lining fluid, alveolar macrophages, bronchial tissue) and nasal secretions.

Following oral administration of gemifloxacin, approximately 36% and 61% of the dose is excreted in the urine and feces, respectively, as unchanged drug and metabolites. AUC values were generally only slightly higher (approx. 10%) in women than in men. No dose adjustment is required based on gender

Gemistar is a quinolone/fluoroquinolone antibiotic. Gemistar is bactericidal and its mode of action depends on blocking of bacterial DNA replication by binding itself to an enzyme called DNA gyrase, which allows the untwisting required to replicate one DNA double helix into two. Notably the drug has 100 times higher affinity for bacterial DNA gyrase than for mammalian. Gemistar is a broad-spectrum antibiotic that is active against both Gram-positive and Gram-negative bacteria.

Trade Name	Gemistar
Availability	Prescription only
Generic	Gemifloxacin
Gemifloxacin Other Names	Gemifloxacin
Related Drugs	amoxicillin, doxycycline, ciprofloxacin, metronidazole, azithromycin, clindamycin, ceftriaxone, levofloxacin
Type	Tablet
Formula	C18H20FN5O4
Weight	Average: 389.3809 Monoisotopic: 389.149932358
Protein binding	60-70%
Groups	Approved, Investigational
Therapeutic Class	4-Quinolone preparations
Manufacturer	Alkem Laboratories Ltd
Available Country	India
Last Updated:	January 7, 2025 at 1:49 am

Uses

Gemistar is used for the treatment of the following bacterial infections in adults caused by sensitive organisms as follows-

Acute bacterial exacerbation of chronic bronchitis: caused by Streptococcus pneumoniae, Haemophilus influenzae, Haemophilus parainfluenzae, or Moraxella catarrhalis.

Community-acquired pneumonia (of mild to moderate severity): caused by Streptococcus pneumoniae (including multi-drug resistant strains), Haemophilus influenzae, Moraxella catarrhalis, Mycoplasma pneumoniae, Chlamydia pneumoniae, or Klebsiella pneumoniae.

Gemistar is also used to associated treatment for these conditions: Acute Bacterial Exacerbation of Chronic Bronchitis (ABECB), Bacterial Infections, Community Acquired Pneumonia (CAP), Gonorrhea, Multidrug resistant Streptococcus pneumoniae infection, Bacterial rhinosinusitis

How Gemistar works

The bactericidal action of gemifloxacin results from inhibition of the enzymes topoisomerase II (DNA gyrase) and topoisomerase IV, which are required for bacterial DNA replication, transcription, repair, and recombination.

Dosage

Side Effects

The general adverse events include abdominal pain, diarrhea, headache, nausea, rash and vomiting. Some side effects have been infrequently reported such as fungal overgrowth in body, dizziness and insomnia, urticaria, pruritis and a maculopapular erythmatous skin rash.

Precaution

Precautions: For patients with severe impairment of renal function, alteration of the dosage regimen to 160 mg once daily is necessary. Adequate hydration of patients receiving Gemistar should be maintained to prevent the formation of a highly concentrated urine and crystalluria. Gemistar may cause dizziness; if this occurs, patients should not operate an automobile or machinery or engage in activities requiring mental alertness or co-ordination.

Warning: Tendinitis and tendon ruptures may occur in any age group during treatment with quinolones, including Gemistar, but particularly in elderly patients or when corticosteroids are being co-administered. Gemistar should be discontinued if tendinitis is suspected or at the first sign of pain or inflammation and the affected limb should be rested. In clinical studies with Gemistar a small mean increase in QTc interval was observed. Gemistar should be used with caution in patients predisposed to QTc interval prolongation or in patients taking other medications that are known to prolong the QTc interval. Gemistar should be used with caution in patients with epilepsy.

Interaction

Gemistar absorption is significantly reduced when aluminium or magnesium containing antacids and iron salts are concomitantly administered. Gemistar should be taken at least 2 hours before or 3 hours after these agents. Gemistar should be taken at least 2 hours before sucralfate administration. No clinically significant interactions have been observed when Gemistar was co-administered with omeprazole theophylline, digoxin, warfarin and oral contraceptives.

Food Interaction

• Take with or without food. The absorption is unaffected by food.

Gemistar multivitamins interaction

[Moderate] ADJUST DOSING INTERVAL: Oral preparations that contain magnesium, aluminum, or calcium may significantly decrease the gastrointestinal absorption of quinolone antibiotics.

Absorption may also be reduced by sucralfate, which contains aluminum, as well as other polyvalent cations such as iron and zinc.

The mechanism is chelation of quinolones by polyvalent cations, forming a complex that is poorly absorbed from the gastrointestinal tract.

The bioavailability of ciprofloxacin has been reported to decrease by as much as 90% when administered with antacids containing aluminum or magnesium hydroxide.

When coadministration cannot be avoided, quinolone antibiotics should be dosed either 2 to 4 hours before or 4 to 6 hours after polyvalent cation-containing products to minimize the potential for interaction.

When coadministered with Suprep Bowel Prep (magnesium

Please consult individual product labeling for specific recommendations.

Drug Interaction

Moderate: citric acid / potassium bicarbonate / sodium bicarbonate, citric acid / potassium bicarbonate / sodium bicarbonateMinor: sulfamethoxazole / trimethoprim, sulfamethoxazole / trimethoprimUnknown: 5-hydroxytryptophan, 5-hydroxytryptophan, contained in alcoholic beverages , contained in alcoholic beverages , amoxicillin / clavulanate, amoxicillin / clavulanate, diphenhydramine, diphenhydramine, diphenhydramine, diphenhydramine, acetaminophen, acetaminophen, penicillin v potassium, penicillin v potassium, cholecalciferol, cholecalciferol

Disease Interaction

Major: colitis, CNS disorders, myasthenia gravis, peripheral neuropathy, QT interval prolongation, tendonitisModerate: crystalluria, diabetes, renal dysfunction

Volume of Distribution

• 1.66 to 12.12 L/kg

Elimination Route

Rapidly absorbed from the gastrointestinal tract. The absolute bioavailability averages approximately 71%.

Half Life

7 (± 2) hours

Clearance

• renal cl=11.6+/- 3.9 L/hr [Healthy subjects receiving repeat doses of 320 mg orally]

Elimination Route

Gemistar and its metabolites are excreted via dual routes of excretion.Following oral administration of gemifloxacin to healthy subjects, a mean (± SD) of 61 ± 9.5% of the dose was excreted in the feces and 36 ± 9.3% in the urine as unchanged drug and metabolites. The mean (± SD) renal clearance following repeat doses of 320 mg was approximately 11.6 ± 3.9 L/hr (range 4.6-6 L/hr), which indicates active secretion is involved in the renal excretion of gemifloxacin.

Pregnancy & Breastfeeding use

Gemistar should not be used in pregnant or lactating women. The safety and efficacy of Gemistar in pregnant or lactating women have not been established.

Contraindication

Known hypersensitivity to Gemistar and other quinolones, Patients who have previously suffered tendon damage with fluoroquinolones. Gemistar should not be used in children under 18 years of age.

Special Warning

Renal impairment: Dose adjustment in patients with mild/moderate renal impairment is not required. Some modification of dosage is recommended for patients with severe renal dysfunction. The following table provides dosage guidelines for use in patients with renal impairment:

Creatinine Clearance (>40 ml/min): See usual dosage

Creatinine Clearance (<40 ml/min): 160 mg once daily

Patients on haemodialysis or continuous ambulatory peritoneal dialysis therapy should receive 160 mg once daily

Hepatic impairment: Gemistar may be given to patients with hepatic impairment, with no requirement for dose adjustment.

Elderly patients: Dose adjustment is not required.

Acute Overdose

No specific antidote is known. Dialysis does not remove Gemistar sufficiently to be useful in overdose. In the event of acute oral overdosage, the stomach should be emptied by inducing vomiting or by gastric lavage; the patient should be carefully observed, treated symptomatically and adequate hydration should be maintained.

Storage Condition

Store in a cool and dry place, protected from light and moisture. Keep out of reach of children.

Innovators Monograph