Amlodipine is a drug mainly used to treat high blood pressure. It is more effective than many other similar medications and has low rates of side effects, making it a good choice for patients. It has also been used to treat a number of other ailments, including chest pain and migraines, as well as several other conditions that are just beginning to be explored by health researchers. Read on to learn more about the uses and risks of amlodipine.
Note: By writing this post, we are not recommending this drug. Some of our readers who were already taking the drug requested that we commission a post on it, and we are simply providing information that is available in the scientific literature. Please discuss your medications with your doctor.
What Is Amlodipine?
Amlodipine is a widely-used drug commonly prescribed for treating high blood pressure and chest pain (angina).
Amlodipine’s main action is to block calcium channels. Calcium channels control how blood vessels throughout the body tighten or relax (more calcium = more tightening). Amlodipine prevents blood vessels from tightening by blocking these channels from taking in more calcium, which leads to lower blood pressure and freer blood flow [R].
Amlodipine is different than other calcium channel blockers as it also releases nitric oxide from blood vessels. Nitric oxide is one of the body’s natural mechanisms for regulating blood flow, and this extra effect may explain why amlodipine is more effective at improving blood pressure [R].
It also increases blood flow to the kidneys, which helps them filter the blood better [R].
How Does Amlodipine Compare to Other Blood Pressure Medications?
Amlodipine is one of many medications that can be prescribed to control blood pressure. By knowing how it compares with other medications, you can assure that you are getting the best drug for your symptoms.
Many commonly-prescribed drugs for high blood pressure are beta and alpha blockers. Beta blockers decrease blood pressure by slowing the heart rate down, and alpha blockers increase blood flow by relaxing the blood vessels. Amlodipine was found to be as effective as both of these types of drugs in reducing blood pressure [R].
Uses of Amlodipine
1) Amlodipine Lowers Blood Pressure
A clinical review of 18 different studies (including data from 1,896 patients in total) concluded that taking amlodipine leads to clinically significant reductions in blood pressure [R].
A study (SB-RCT) with 50 patients found that high blood pressure returned to normal levels in 80% of patients who took amlodipine, compared to only 50% of the patients who took a diuretic (hydrochlorothiazide) [R].
If you happen to be forgetful, amlodipine may be your drug of choice, as it was shown to both lower and maintain blood pressure better than losartan after 2 missed doses in a study (DB-RCT) with 211 elderly patients with high blood pressure [R].
Although blood pressure problems are relatively rare among young people, amlodipine may also be used to lower blood pressure in children. In a study (DB-PCT) with 268 children, amlodipine lowered systolic blood pressure with very low rates of side effects [R].
2) Amlodipine Effectively Treats Angina (Chest Pain)
A study (DB-RCT) in 52 angina patients found that amlodipine greatly reduced the number of angina episodes after just 4 weeks of daily treatment. It was also relatively safe, with swelling in the limbs (peripheral edema) as the only reported side effect [R].
Similarly, in a large-scale study (DB-RCT) of 825 patients with coronary heart disease (which can lead to angina). amlodipine reduced the number of sudden (“unstable”) angina episodes over a 3-year period [R].
Amlodipine reduced the number of angina episodes in another study (DB-RCT) of 29 angina patients. Amlodipine also increased the amount of time that patients could exercise (“exercise tolerance”), suggesting that amlodipine might have a beneficial effect on circulation in general [R].
3) Amlodipine May Correct Some Heart Abnormalities
The left ventricle is a large part of the human heart that is the last “stop” for your blood before it passes to the rest of your body (through the aortic valve). However, the size of the left ventricle (ventricular mass) can sometimes grow abnormally large, which can be an indication of a larger problem. For example, a study with 774 young adults found that an increased left ventricular mass was associated with an increased risk of high blood pressure (hypertension) [R].
However, a study found that amlodipine and lisinopril (another popular blood pressure medication) were equally effective in returning the left ventricle to a more normal size, suggesting that these drugs may also help treat other underlying factors that may be contributing to elevated blood pressure [R].
4) Amlodipine May Prevent Side Effects from Arthritis Treatment
Several of the drugs commonly prescribed to arthritis patients to treat their symptoms have the side effect of raising blood pressure. A study (DB-PCT) in arthritis patients who were taking the common arthritis medication indomethacin found that amlodipine was more effective than enalapril (another common blood pressure medication) at preventing these side effects [R].
5) Amlodipine May Reduce the Risk of Dementia in the Elderly
High blood pressure (hypertension) has been linked to an increased risk for developing dementia, although most drugs that treat high blood pressure have not been shown to decrease the long-term risk of dementia. However, amlodipine was associated with significantly reduced risk of dementia in patients who were >60 years old in a large-scale study with 15,664 patients taking various blood pressure-reducing medications [R].
6) Amlodipine May Help Prevent or Treat Opioid Addiction
People who take opioid painkillers for extended periods of time gradually develop tolerance, eventually requiring higher and higher doses of opioids to achieve the same effects. They also experience an increased sensitivity to pain (hyperalgesia) after they stop taking opioids, which can make it even harder to successfully quit using these drugs.
However, several mouse studies have found that amlodipine may be able to prevent both of these side effects of opioid use. Amlodipine shows potential for preventing or treating opioid addiction in humans, although more studies need to confirm this [R, R, R].
7) Amlodipine May Help Reduce Migraines
Calcium channel blockers (like amlodipine) have been used in the past to prevent migraines. A series of case studies in migraine patients found that amlodipine reduced the number of migraines, or even stopped them altogether. Although it has not yet been studied enough to get official FDA approval for this use, these early reports indicate that amlodipine may be useful for controlling migraines when prescribed “off-label” [R].
Combining Amlodipine with Other Drugs
Many different systems in the body are involved in controlling blood pressure. Since each blood pressure medication only affects one of these systems at a time, by using multiple drugs together it is possible to target several of these systems at once [R, R].
Combining amlodipine with the following drugs can increase its effectiveness:
- Aliskiren: A study with 1,247 patients (DB-RCT) found that a combination of amlodipine with aliskiren was more effective in reducing blood pressure than amlodipine alone [R].
- Telmisartan: A study with 300 patients found that a steady dose of amlodipine became more effective as telmisartan doses were increased [R].
- Olmesartan: A variety of studies have found that adding olmesartan to amlodipine treatment is not only more effective at lowering blood pressure, but also reduces the side effects of amlodipine [R].
- Valsartan: A study (DB-RCT) with 443 patients who were originally on only one medication (monotherapy) found that a combination drug containing both amlodipine and valsartan (also called exforge) controlled blood pressure better [R].
In a double-blind study with 3 different drugs (olmesartan, amlodipine, and hydrochlorothiazide), the combination of all 3 lowered blood pressure more than just the combination of amlodipine and olmesartan, or any single drug on its own [R].
The combinations used in all of these studies were found to be safe, with minimal side effects.
Amlodipine Side Effects
Amlodipine has generally low rates of side effects. According to a large-scale study involving 12,831 patients, only 3% of all patients decided to stop taking amlodipine due to side effects [R].
A study (PCT) with 97 patients found that amlodipine had a significantly lower rate of side effects compared to nifedipine, a similar blood pressure medication [R].
A large-scale analysis of data from over 11,000 patients found that the side effects of amlodipine were relatively rare, and included a headache (in 7% of patients), abdominal pain (2%), fatigue (5%), and nausea (3%) [R, R].
- Swelling or inflammation (edema)
- Muscle cramps
- Heart palpitations
- Increased heart rate
- Nosebleeds (epistaxis)
- Swollen eyes or “pink eye” (conjunctivitis)
- Increased frequency of urination, or sleep interruptions from having to urinate (nocturia)
- Itchiness throughout the body (generalized pruritus)
Safety of Amlodipine
A number of earlier studies suggested that the long-term use of calcium channel blockers might increase the risk of sudden death in patients with chronic heart failure. However, a large-scale study (DB-PCT) with 1,153 patients with heart failure found that long-term use of amlodipine actually reduced mortality rates by 16% [R].
Amlodipine appears to be safe to use while pregnant and has not been associated with birth defects or changes in the birth weight of children. It is also safe to use while breastfeeding and does not cause any toxic effects on the developing child [R, R].
Limitations and Caveats
While many studies have found amlodipine to be safer and more effective than most other blood pressure drugs, there have been a few exceptions.
One study compared amlodipine to fosinopril (Monopril), an enzyme inhibitor that relaxes the blood vessels, leading to improved blood flow. Although both medications were equally effective at reducing blood pressure, fosinopril had the additional benefit of reducing the risk of major vascular events (such as heart attacks and strokes) over a 3-year period [R].
In one other study in 421 elderly patients, amlodipine was as effective as valsartan at lowering blood pressure, but that valsartan had fewer side effects than amlodipine [R].
There are some drugs that have some major interactions with amlodipine that are important to be aware of:
- Aspirin and amlodipine both bind to the same protein in the blood (albumin), which helps to control how much of each is active in the bloodstream. Taking both drugs together means that they will each compete for binding to this protein, which can lead to dangerously high levels of the active drugs circulating throughout the body [R].
- Ibuprofen and piroxicam may decrease the effects of amlodipine, reducing its ability to lower blood pressure [R].
- Cyclosporine: Amlodipine can increase the amount of cyclosporine that is absorbed into the bloodstream by as much as 40%, leading to much higher doses of cyclosporine than intended [R].
- Simvastatin (FloLipid, Zocor, Juvisync): Amlodipine can increase the amount of simvastatin that gets absorbed into the bloodstream, although this does not appear to strengthen its cholesterol-reducing effects [R]
However, there are also many more potential drug interactions. Therefore, it is important to give your doctor a complete list of any vitamins, supplements, or other drugs you are taking when getting a prescription for a blood pressure medication.
A typical dose of amlodipine is generally between 5 to 10mg / day, although this may vary between individuals and can only be determined by your prescribing doctor. Also note that your doctor may start you off on a small dose, and increase it gradually as needed.
More than 90% of the drug is directly absorbed by your body, and it stays in your bloodstream for up to 2 days or more [R].
Fortunately, amlodipine doesn’t need to be taken at the exact same time every day in order to be effective. It will reach a steady level in your body after about 7 to 8 days of taking it, and will stay at a relatively constant level afterward as long as you don’t miss too many of your daily doses [R, R].
Blood pressure medications can be taken either in a single large daily dose or split into 2 smaller doses taken twice per day. However, a study on drug compliance found that people are generally less likely to miss a dose when taking a once-per-day dosage—so if you tend to be forgetful, it might be best to ask your doctor to prescribe you a single larger dose [R].
Because amlodipine is used to lower high blood pressure, taking too much of it at once could cause severely low blood pressure (hypotension), which could be fatal.
Although the amount that it would take to cause death in a human is unknown, data from overdose studies in animals suggest that the equivalent human dose would be extremely large, amounting to many times more than even the largest typical daily dose [R].
For example, there is a case study of a young teenage girl who attempted suicide by taking 150 mg of amlodipine (equivalent to about 15 to 30 pills at once). She was taken to the hospital approximately 4 hours after and survived with a full recovery [R].
In one other case, a 51-year-old male successfully committed suicide by taking 50 pills of amlodipine [R].
Since the typical dose of amlodipine is only 5 to 10mg, the risk of accidentally overdosing on amlodipine is quite small so long as it is being taken as directed.
Nonetheless, since this drug is fairly common in the household, it is very important to keep it stored safely and out of the reach of children. There was a reported case of a 19-month-old child accidentally ingesting 30 mg, although it was non-fatal and the child eventually made a full recovery [R].
There are many positive reviews for amlodipine, with many individuals praising how effective it has been at reducing their blood pressure. However, some others have reported that the side effects they experienced were severe enough to convince them to stop taking the drug.
Below are some of the positive experiences people have reported:
- One woman who had recently developed acute hypertension said that each day of taking amlodipine reduced her blood pressure more and more.
- One 65-year-old has been taking amlodipine for 10 years and has been very happy with the drug, apart from swollen feet (which were controlled with a diuretic). This person achieved a steady blood pressure with no other reported side effects.
- Another woman who has taken amlodipine for more than 10 years says her blood pressure without this drug is deadly, but that amlodipine has helped her keep it down to a safe level.
- One other user said when the medicine made them groggy, they split up their dose, which stopped the side effects completely. They are now very happy with this drug and its benefits.
- One person who has taken amlodipine for 15 years reported a healthy blood pressure level as well as complete elimination of his chronic migraines. This person’s experience is similar to those of many others who also report that this drug cured their migraines.
However, other people have had negative experiences with this drug, such as the following:
- One person said they have seen no significant differences in their high blood pressure and have been having constant leg cramps, shortness of breath, and weight gain. However, they did say that they no longer have any migraines.
- Another person who only took this drug for a month said it made her have a very fast heart rate that disturbed her sleep, causing her to feel exhausted all of the time.
- A 56-year-old woman had slightly high blood pressure but stopped taking her amlodipine prescription because she felt that the side effects did not outweigh the benefits. She said she was currently working to switch to a new medication.
- One person who took amlodipine for 2 years said they eventually decided the extreme swelling in their legs was not worth it, and that they lost 8 pounds of water weight after they finally stopped taking it.