Gyrablock (Norfloxacin)

Gyrablock (norfloxacin) is prescribed for a range of bacterial infections that are susceptible to fluoroquinolone therapy.

• Uncomplicated urinary tract infections caused by susceptible Gram‑negative organisms.
• Acute bacterial prostatitis when oral therapy is indicated.
• Gastrointestinal infections such as shigellosis or travel‑associated diarrhoea.
• Certain enteric infections caused by susceptible Salmonella or Campylobacter species.
• Prophylaxis or treatment of infections where other agents are contraindicated or ineffective.
• Respiratory tract infections such as community‑acquired pneumonia caused by susceptible organisms.
• Skin and soft‑tissue infections when fluoroquinolone therapy is appropriate.

Like other fluoroquinolones, Gyrablock may cause a range of adverse effects, most of which are mild and reversible, while a few can be serious.

Common

• Nausea or upset stomach, usually mild and transient.
• Diarrhoea or loose stools, which may resolve after treatment ends.
• Headache, ranging from mild to moderate intensity.
• Dizziness or light‑headedness, often occurring shortly after dosing.

Serious

• Tendonitis or tendon rupture, particularly of the Achilles tendon, which may require medical evaluation.
• Prolongation of the QT interval on electrocardiogram, potentially leading to cardiac arrhythmias.
• Severe hypersensitivity reactions, including Stevens‑Johnson syndrome, toxic epidermal necrolysis, or anaphylaxis.

Before prescribing Gyrablock, clinicians should evaluate patient history and risk factors because fluoroquinolones carry specific safety considerations.

• Do not use in patients with known hypersensitivity to norfloxacin or other fluoroquinolones.
• Exercise caution in individuals with a history of tendon disorders or recent corticosteroid use.
• Avoid use during pregnancy or breastfeeding unless the potential benefit outweighs the risk.
• Assess renal function and adjust dosing in patients with significant impairment.
• Monitor for QT interval prolongation in patients with existing cardiac disease or electrolyte abnormalities.
• Use carefully in the elderly, who may be more susceptible to CNS effects.
• Evaluate blood glucose control in diabetic patients, as fluoroquinolones can affect glucose levels.

Gyrablock can interact with several medicines, altering its effectiveness or increasing the risk of adverse events.

Avoid

• Antacids, supplements, or multivitamins containing magnesium, aluminum, calcium, iron, or zinc, which can reduce norfloxacin absorption.
• Warfarin, as norfloxacin may enhance anticoagulant effects and increase bleeding risk.
• Other drugs known to prolong the QT interval, which may compound cardiac rhythm disturbances.

Use with caution

• Systemic corticosteroids, due to an increased risk of tendon injury.
• Oral hypoglycemic agents or insulin, because norfloxacin may affect blood glucose levels.
• Theophylline, as norfloxacin can raise plasma concentrations and increase toxicity risk.