NORBROOK MILKING SALVE

Indications

• Allergic rhinitis
• Urticaria
• Allergic conjunctivitis
• Motion sickness
• Insomnia associated with allergies

Dosage

Children: Refer to the BNF for Children for specific dosing information.

Adults: Refer to the BNF for specific dosing information.

Mechanism of action

Dichlorphen acts as a competitive antagonist of histamine at the H1 receptor sites, thereby inhibiting the effects of histamine in the body. This results in a reduction of symptoms associated with allergic reactions, such as itching, sneezing, and runny nose. Additionally, it may exert some anticholinergic effects, contributing to its sedative properties.

Pharmacodynamics

Dichlorphen demonstrates a range of pharmacological effects including antihistaminic, sedative, and anticholinergic actions. Its antihistamine activity is responsible for alleviating allergic symptoms, while the sedative effect can aid in the management of insomnia or anxiety related to allergic conditions. The anticholinergic properties may help reduce secretions and provide relief in cases of motion sickness.

Pharmacokinetics

Dichlorphen is absorbed well from the gastrointestinal tract and reaches peak plasma concentrations within a few hours of oral administration. It is extensively metabolized in the liver, and the metabolites are primarily excreted in urine. The half-life of dichlorphen varies, but it generally ranges from 4 to 8 hours, allowing for multiple dosing throughout the day depending on the clinical indication.

Contra-indications

• Hypersensitivity to dichlorphen or any of its components
• Severe liver impairment
• Porphyria

Adverse effects

• Drowsiness
• Dizziness
• Dry mouth
• Constipation
• Nausea
• Vomiting
• Headache
• Allergic reactions such as rash or urticaria

Interactions

• May enhance the effects of alcohol and other central nervous system depressants
• May interact with anticholinergic drugs
• Caution with concomitant use of medications that affect liver enzymes

Precautions

• Use with caution in patients with a history of drug abuse
• Caution in elderly patients due to increased sensitivity
• Monitor for sedation and anticholinergic effects
• Use in patients with narrow-angle glaucoma or urinary retention should be carefully considered

Pregnancy

Dichlorphen should only be used in pregnancy if the potential benefit justifies the potential risk to the fetus. Consult relevant guidelines and consider alternatives.

Breast-feeding

It is not known whether dichlorphen is excreted in human milk. Caution should be exercised when administering to nursing women.

Storage

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

Formulations

• Tablets
• Liquid preparations