Votaren Gel

Indications

• Acute pain
• Chronic pain conditions
• Osteoarthritis
• Rheumatoid arthritis
• Ankylosing spondylitis
• Menstrual pain
• Postoperative pain

Dosage

Children: Refer to BNF for Children for age-appropriate dosing recommendations.

Adults: Refer to BNF for specific dosing guidelines according to the condition being treated.

Mechanism of action

Diclofenac exerts its effects primarily by inhibiting cyclooxygenase (COX-1 and COX-2) enzymes. This inhibition decreases the production of prostaglandins, which are mediators of inflammation, pain, and fever. By reducing prostaglandin levels, diclofenac alleviates pain and inflammation associated with various conditions.

Pharmacodynamics

The pharmacodynamic effects of diclofenac include the reduction of inflammation, pain relief, and antipyretic effects. By modulating the COX pathways, diclofenac effectively decreases the sensitivity of pain receptors and reduces swelling and redness in inflamed tissues. Its potency can vary based on formulation and individual patient factors.

Pharmacokinetics

Diclofenac is well absorbed after oral administration, with peak plasma concentrations occurring within 1-2 hours. It is extensively metabolized in the liver, primarily by cytochrome P450 enzymes, to form active metabolites. The elimination half-life is approximately 1-2 hours, and it is excreted mainly via the urine. The pharmacokinetics may be influenced by factors such as age, liver function, and the presence of other medications.

Contra-indications

• Active peptic ulcer disease
• History of gastrointestinal bleeding or perforation related to previous NSAID therapy
• Severe heart failure
• Caution in patients with renal impairment

Adverse effects

• Gastrointestinal disturbances (nausea, vomiting, diarrhea, constipation)
• Headache
• Dizziness
• Increased blood pressure
• Skin rashes
• Renal impairment

Interactions

• Ciclosporin: Unknown (increases concentration)
• Iron chelators: Unknown (increases exposure)
• Deferiprone: Unknown (increases exposure)

Precautions

• Use with caution in patients with a history of cardiovascular disease
• Monitor renal function during long-term therapy
• Consider alternative analgesics in patients with a history of peptic ulcer disease

Pregnancy

Use during pregnancy should be avoided, especially in the third trimester due to potential risks to the fetus and complications during delivery.

Breast-feeding

Use with caution; minimal amounts may be excreted in breast milk.

Storage

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

Formulations

• Oral tablets
• Topical gels or creams
• Intramuscular injection

Mechanism of action

Diethylamine acts primarily as a weak base, facilitating nucleophilic substitution reactions. Its basicity allows it to accept protons, which can enhance the reactivity of other compounds in chemical processes.

Pharmacodynamics

The pharmacodynamic properties of diethylamine are largely related to its role as a chemical reagent rather than a pharmaceutical agent. It does not exert therapeutic effects in the same way that many drugs do but is involved in various chemical pathways as a reactant.

Pharmacokinetics

Detailed pharmacokinetic data for diethylamine is limited due to its primary use in laboratory and industrial applications rather than as a therapeutic agent. However, it is expected to be readily absorbed through mucous membranes and the skin, with potential metabolic pathways involving N-dealkylation and oxidation.

Pregnancy

There is limited data on the use of diethylamine in pregnancy. Caution is advised.

Breast-feeding

There is insufficient data on the excretion of diethylamine in human milk. Caution is advised.

Storage

Store in a cool, dry place, away from light.