HEXASOL LA INJECTION

Indications

• Pain relief in inflammatory conditions
• Osteoarthritis
• Colic in horses
• Post-operative pain management

Dosage

Children: Refer to the BNF for Children for specific dosing recommendations in paediatric patients.

Adults: Refer to the BNF for specific dosing recommendations based on the condition being treated.

Mechanism of action

Flunixin exerts its effects primarily by inhibiting the enzyme cyclooxygenase (COX), which is crucial in the synthesis of prostaglandins from arachidonic acid. This inhibition results in decreased levels of prostaglandins, leading to reduced inflammation, pain, and fever. Flunixin preferentially inhibits COX-2, which is responsible for the inflammatory response, while having a lesser effect on COX-1, which protects the gastric mucosa.

Pharmacodynamics

Flunixin is known for its potent anti-inflammatory and analgesic effects. It is effective in reducing pain and swelling associated with various inflammatory conditions. The onset of action is typically rapid, with effects seen within a few hours of administration. The duration of action can vary depending on the route of administration and the specific condition being treated.

Pharmacokinetics

Flunixin is well absorbed following oral administration, with peak plasma concentrations occurring within 1 to 2 hours. It has a volume of distribution that suggests extensive tissue binding. Flunixin is primarily metabolized in the liver, and its metabolites are excreted mainly in the urine. The elimination half-life is approximately 3 to 6 hours in humans, though this may vary based on individual patient factors.

Contra-indications

• Hypersensitivity to flunixin or any of its components
• Active gastrointestinal bleeding
• Severe renal impairment
• Active liver disease

Adverse effects

• Gastrointestinal ulceration
• Gastrointestinal bleeding
• Renal toxicity
• Hepatotoxicity
• Anaphylaxis
• Injection site reactions

Interactions

• Concurrent use with other NSAIDs may increase the risk of gastrointestinal toxicity
• Caution with anticoagulants due to potential increased bleeding risk
• May enhance the effects of other drugs that are renally excreted

Precautions

• Use with caution in patients with pre-existing kidney or liver disease
• Monitor for signs of gastrointestinal bleeding
• Avoid use in dehydrated animals or those with hypovolaemia
• Consider potential effects on platelet function

Pregnancy

Flunixin should only be used during pregnancy if the potential benefits justify the risks to the fetus, as safety in pregnancy has not been established.

Breast-feeding

It is not known whether flunixin is excreted in human milk; caution should be exercised when administering to breastfeeding mothers.

Storage

Store at room temperature, away from moisture and heat. Protect from light.

Formulations

• Injectable solution
• Oral suspension
• Tablets

Indications

• Bacterial infections (e.g. Chlamydia, Rickettsia, Mycoplasma)
• Acne
• Prophylaxis of asymptomatic meningococcal carrier state (not recommended)

Dosage

Adults: For adult patients, the typical dosage of oxytetracycline for susceptible infections is 100 mg twice daily for 5 days. For other conditions, such as acne, the dosage may be 500 mg twice daily, usually for a duration of 6 to 12 weeks, with the possibility of repeating the course intermittently.

Mechanism of action

Oxytetracycline exerts its antibacterial effects by binding to the 30S ribosomal subunit of bacteria, inhibiting the binding of aminoacyl-tRNA to the mRNA-ribosome complex. This action prevents the synthesis of proteins essential for bacterial growth and replication, leading to the bacteriostatic effect of the drug.

Pharmacodynamics

The pharmacodynamics of oxytetracycline involve its ability to inhibit bacterial protein synthesis, which is critical for the growth and reproduction of bacteria. The drug demonstrates a broad spectrum of activity against both Gram-positive and Gram-negative organisms, as well as some atypical pathogens. Its effectiveness can be influenced by the presence of tetracycline resistance mechanisms in certain bacterial strains.

Pharmacokinetics

Oxytetracycline is well absorbed from the gastrointestinal tract, with peak plasma concentrations occurring approximately 1-2 hours after oral administration. It has a relatively long half-life of about 8-10 hours, allowing for twice-daily dosing. The drug is widely distributed in body tissues and fluids, including the liver, kidneys, and lungs, but is less effective in central nervous system infections due to limited penetration. It is primarily excreted via urine, and dosage adjustments may be necessary in patients with renal impairment.

Contra-indications

• Children under 12 years due to deposition in growing bone and teeth, causing staining and occasionally dental hypoplasia

Adverse effects

• Gastrointestinal disturbances
• Photosensitivity
• Dental discoloration
• Hepatotoxicity
• Renal impairment
• Skin reactions including rash and urticaria
• Ataxia
• Hearing impairment
• Colitis
• Systemic lupus erythematosus exacerbation

Interactions

• Antacids and supplements containing calcium, magnesium, or iron may reduce absorption
• Oral contraceptives may be less effective
• Other tetracyclines
• Warfarin (may increase anticoagulant effect)

Precautions

• Use with caution in patients with renal impairment
• Monitor for hepatic toxicity in long-term use
• Patients should be advised to avoid excessive sunlight exposure
• Discontinue if systemic lupus erythematosus develops or worsens

Pregnancy

Oxytetracycline is contraindicated during pregnancy due to potential harm to fetal development, particularly affecting bone and dental health.

Breast-feeding

Use with caution; oxytetracycline is excreted in breast milk and may affect the infant's dental health.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Oxytetracycline 250 mg tablets
• Oxytetracycline oral suspension
• Oxytetracycline oral solution