BROMIDES, POTASSIUM BROMIDE, SODIUM BROMIDE

Chemistry - Potassium bromide occurs as white, odorless, cubical crystals or crystalline powder.
One gram will dissolve in 1.5 ml of water. Potassium bromide contains 67.2% bromide. Each gramcontains 8.4 mEq (mmol) of potassium and bromide.
Sodium bromide occurs as white, odorless, cubic crystals or granular powder. One gram willdissolve in 1.2 ml of water. Sodium bromide contains 77.7% bromide.

Storage, Stability, Compatibility

Store in tight containers. Bromides can precipitate out alkaloids in solution. Mixing with strong oxidizing agents can liberate bromine. Metal salts can precipitate solutions containing bromides. Sodium bromide is hygroscopic; potassium bromide is not.

Pharmacology - BROMIDES, POTASSIUM BROMIDE, SODIUM BROMIDE

Bromide's anti-seizure activity is thought to be the result of its generalized depressant effects on neuronal excitability and activity. Bromide ions compete with chloride transport across cell membranes resulting in membrane hyperpolarization, thereby raising seizure threshold and limiting the spread of epileptic discharges.

Uses, Indications

Bromides are used as adjunctive therapy to control seizures in dogs who arenot adequately controlled by phenobarbital (or primidone) alone. In patients suffering from phenobarbital (or primidone) hepatotoxicity, bromides may be used alone (renally excreted). Earlyindications are that approximately 50% of dogs show improvement in seizure control after the addition of bromides.

Pharmacokinetics - BROMIDES, POTASSIUM BROMIDE, SODIUM BROMIDE

Bromides are well absorbed after oral administration, primarily in the smallintestine. Bromide is distributed in the extracellular fluid and mimics the volume of distribution ofchloride (0.2-0.4 L/Kg). It is not bound to plasma proteins and readily enters the CSF (in dogs:87% of serum concentration; in humans: 37%). Bromides enter maternal milk (see reproductivesafety below). Bromides are principally excreted by the kidneys. The half life in dogs has beenreported to be about 25 days; in humans, 12 days.

Contraindications, Precautions, Reproductive Safety

Older animals and those with additionaldiseases, may be prone to intolerance (see side effects below) at blood levels that are easily tolerableby younger, more healthy dogs.
Reproductive safety has not been established. Human infants have suffered bromide intoxicationand growth retardation after maternal ingestion of bromides during pregnancy. Bromide intoxication has also been reported in human infants breast feeding from mothers taking bromides.

Adverse Effects, Warnings

A transient sedation (lasting up to 3 weeks) is commonly seen indogs receiving bromides in addition to phenobarbital. Toxicity generally presents as profoundsedation to stupor, ataxia, tremors, or other CNS manifestations. Pancreatitis has been reported indogs receiving combination therapy of bromides with either primidone or phenobarbital. However, since this effect has been reported with both primidone and phenobarbital, its relationship withbromide is unknown. Additional potential adverse effects reported include, anorexia, vomiting, andconstipation. Rashes have been reported in humans taking bromides.
If administering an oral loading dose of potassium bromide, acute GI upset may occur if given toorapidly. Potentially, large loading doses could affect serum potassium levels in patients receivingpotassium bromide.

Overdosage, Acute Toxicity

Toxicity is more likely with chronic overdoses, but acute overdosesare a possibility. In addition to the adverse effects noted above, animals who have developedbromism (whether acute or chronic) may develop signs of muscle pain, conscious proprioceptivedeficits, anisocoria, and hyporeflexia.
Standard gut removal techniques should be employed after a known acute overdose. Death after anacute oral ingestion is apparently rare, as vomition generally occurs spontaneously. Administrationof parenteral or oral sodium chloride, parenteral glucose and diuretics (e.g., furosemide) may behelpful in reducing bromide loads in either acutely or chronically intoxicated individuals.

Drug Interactions

Bromide toxicity can occur if chloride ion ingestion is markedly reduced.
Patients put on low salt diets may be at risk. Conversely, additional sodium chloride in the dietcould reduce serum bromide levels, affecting seizure control. Because bromides can cause sedation, other CNS sedating drugs may cause additive sedation. Diuretics may enhance the excretion ofbromides thereby affecting dosage requirements.
Laboratory Considerations - See drug interactions above regarding chloride.