Basic Information:

• Mechanism: Amlodipine works by inhibiting the influx of calcium ions into vascular smooth muscle and cardiac muscle cells. This action helps dilate the blood vessels, reducing blood pressure and decreasing the heart's workload.
• Absorption: Amlodipine is well-absorbed orally and can be given with or without food. Its effects are gradual, with peak efficacy reached over several hours.

Dogs and Cats:

• Applications: In cats, amlodipine is commonly used to treat hypertension associated with kidney disease, hyperthyroidism, or heart disease. In dogs, it's used less frequently but can be effective in treating hypertension related to chronic kidney disease or heart failure.
• Administration: Typically administered once daily due to its long half-life, which supports stable blood pressure control throughout the day.

Side Effects:

• Common side effects include lethargy, gastrointestinal disturbances such as vomiting or loss of appetite, and, in some cases, gum swelling or an increased heart rate. These effects are relatively rare.
• Serious side effects necessitate immediate veterinary attention, such as signs of shock or allergic reactions like facial swelling or hives.

Precautions:

• Amlodipine should be used with caution in pets with severe cardiac or liver disease due to its effects on the heart and its metabolism in the liver.
• Not recommended for use in pregnant or lactating animals, or those with a history of hypersensitivity to the drug.

Drug Interactions:

• Care should be taken when amlodipine is used in conjunction with other medications that lower blood pressure, as this can lead to excessive hypotension.
• Interaction with grapefruit juice can alter the metabolism of amlodipine, potentially leading to increased drug levels and risk of side effects.

Overdose:

• Overdose of amlodipine can lead to dangerously low blood pressure, profound weakness, and collapse.
• Immediate veterinary intervention is crucial, including therapies such as intravenous fluids, vasopressors to support blood pressure, and monitoring for cardiac rhythm disturbances.