Cilnidipine is a calcium channel blocker medication used to treat hypertension, also known as high blood pressure. It functions by inhibiting calcium influx into the smooth muscle cells of blood vessels. This action causes the blood vessels to relax and widen, which lowers blood pressure and allows blood to flow more easily.
This medication acts on both L-type and N-type calcium channels. The effect on L-type channels produces the primary blood pressure-lowering result. Its action on N-type channels helps suppress the release of norepinephrine, a neurotransmitter that can increase heart rate and blood pressure in response to stress, allowing for effective blood pressure control.
Standard Dosing Guidelines
Standard treatment with cilnidipine for an adult begins with a starting dose of 5 mg to 10 mg, taken once per day. This initial amount allows a healthcare provider to assess the patient’s response and tolerance. The dose should be taken at a consistent time each day, such as after breakfast, to maintain stable concentrations of the drug in the bloodstream.
Based on the individual’s blood pressure readings and clinical response, the dosage may be adjusted. The maintenance dose remains in the 5 mg to 10 mg once-daily range for most patients. If blood pressure remains elevated, a physician may increase the daily amount.
For patients who require a stronger effect, the dose can be increased. The maximum recommended daily dose of cilnidipine is 20 mg, taken once a day. Dosages beyond this amount are not recommended as they increase the risk of adverse effects without providing significant additional benefit in blood pressure reduction. All dosage adjustments should be made by a doctor.
Factors Influencing Dosage Adjustments
A physician personalizes the cilnidipine dose based on several patient-specific factors. The severity of a person’s hypertension is a primary consideration, as higher blood pressure readings may require a dose at the upper end of the standard range. A patient’s response to the initial treatment also guides subsequent changes to their prescribed amount.
Age is another consideration, as elderly patients may metabolize medications more slowly. This can lead to higher drug concentrations in the blood, increasing the risk of side effects like dizziness or an excessive drop in blood pressure. As a result, older individuals are often started on a lower dose, and any increases are made with caution.
Pre-existing health conditions, especially liver impairment, influence dosage decisions. Since cilnidipine is metabolized by the liver, compromised function can lead to its accumulation and amplify the medication’s effects. Patients with severe hepatic impairment require a lower or more cautiously adjusted dose.
Managing Missed or Extra Doses
If a dose is missed, it should be taken as soon as it is remembered. This helps maintain a consistent level of the medication in the body for stable blood pressure control.
If it is almost time for the next scheduled dose, the missed one should be skipped entirely. The patient should then resume their regular dosing schedule. Do not take a double dose to compensate for the one that was missed, as this can lead to an unsafe drop in blood pressure.
An overdose of cilnidipine can cause profound hypotension, or extremely low blood pressure. Symptoms may include severe dizziness, fainting, confusion, slurred speech, or a slow or irregular heartbeat. If an overdose is suspected, seek immediate medical attention or contact a poison control center.
Interactions Affecting Cilnidipine Levels
The concentration of cilnidipine in the body can be altered by certain medications, substances, and foods. When taken with other antihypertensive drugs, the combined effect can lead to an excessive drop in blood pressure. Certain antifungal medications and some antibiotics can also interfere with how cilnidipine is metabolized, increasing its levels in the blood.
A significant interaction occurs with grapefruit and grapefruit juice. Cilnidipine is broken down by the CYP3A4 enzyme in the liver and intestines. Grapefruit contains compounds that inhibit this enzyme’s action, causing more of the drug to be absorbed into the bloodstream. This leads to higher concentrations and an increased risk of side effects like dizziness and flushing.
It is important for patients to inform a doctor and pharmacist of all other medications being taken, including over-the-counter drugs, supplements, and herbal products. This allows them to screen for potential interactions and make appropriate adjustments to the treatment plan to ensure safety.