An accurately weighed amount of the powders, containing the immediate release layer and the rate modulating layers, were sifted through 80 mesh size, and then tablets were compressed in a 7 mm single punch machine by hand filling. The immediate release layer was composed of verapamil: lactose: cross povidone: magnesium stearate , while the rate modulating membrane was composed of polymers only.
HPMC K15, chitosan and sodium alginate alone, and chitosan and sodium alginate in different proportions at different weights , , mg were compressed. To study the amount of bulking agent on the release of drug, lactose and sodium bicarbonate:citric acid were used as bulking agents. Two layered tablets containing the immediate release and the rate modulating layer, followed by the effervescent layer and lactose as filler were snuggly fitted in the impermeable capsule body Fig.
The first two layered tablet A was placed in the capsule body in such a way that the immediate release layer was facing the outer side, while the rate modulating layer faced inside. The layers rate modulating and immediate release layer of the second two layered tablet B were position facing the opposite way to first two layered tablet. A total of mL of the dissolution medium pH 1. After 2 h stirring was stopped, the basket was washed with distilled water and the dissolution medium was replaced by phosphate buffer pH 6.
Aliquots 10 mL were withdrawn at 15 min time intervals and the same volume replaced by fresh dissolution medium. The aim of the study was to develop a pH independent dosage form with a lag time of 6 h and fast release thereafter. The total weight of the layered tablet was kept at mg for the study. Only 7. From Figure 2 , it was also seen that chitosan and sodium alginate were not able to produce the desired lag time at maximum weight, and that lag time was dependent on the pH of the medium.
Sodium alginate rapidly forms a viscous gel on contact with aqueous media. Because of its high dissolution characteristics, the drug rapidly diffuses through the gel and released all of its active ingredient in 3 h, at the highest weight of polymer.
Chitosan dissolves to some extent in inorganic mineral acids, hence providing the higher lag time of 4 h and the drug was released by initial low dissolution and then erosion of chitosan. A combination of chitosan with sodium alginate for sustaining the release of theophylline has also been studied, and release was found to be independent of the pH of the dissolution medium Yamota et al. From the results, shown below Figure 3 , it was found that a lag time of 3 h was obtained from CSAS at a ratio at mg weight.
The complex produced by combining the chitosan and sodium alginate had no significant effect over chitosan and sodium alginate alone. Similar results were also obtained by Jittima and co-workers Chatchawalsaisin et al. SBCM was added to hasten the release of drug after the desired lag time. No effect was observed at low amounts of SBCM Figure 4 , but at higher amounts the lag time was found to be reduced due to the pressure generated in the system by CO 2 after dissolution of SBCM causing pressure on the gel matrix.
Verapamil is a basic drug which is why the dissolution of the drug was also reduced as SBCM was increased. Lactose was added as a bulking agent separately to ensure the proper position of the tablet in the capsule device, but a significant effect on the lag time of drug due to the amount of lactose was observed Figure 5.
The increasing hydrodynamic pressure in the system, due to dissolution of lactose, shortened the lag time. From the above results, two pulse release was successfully achieved Figure 6 by using a bi-layered tablet containing mg of immediate release layer and mg of HPMC K 15 as a rate modulating layer, followed by mg of CSAC as a rate modulating layer, mg of immediate release layer, and 20 mg SBCM and mg of lactose. Verapamil can increase the amount of eletriptan in your body to 3 times as much.
This can lead to toxic effects. Combining blood pressure-lowering drugs with verapamil can lower your blood pressure to a dangerous level. If your doctor prescribes these drugs with verapamil, they will monitor your blood pressure closely. Your doctor will monitor your levels of these drugs if you are also given verapamil.
The following drugs may decrease the levels of verapamil in your body:. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions.
Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.
Taking it again could be fatal. Grapefruit juice: Grapefruit juice may increase the amount of verapamil in your body. This may lead to increased side effects. Avoid drinking grapefruit juice while taking verapamil.
Verapamil may increase the amount of alcohol in your blood and make alcohol effects continue longer. Alcohol may also make the effects of verapamil stronger. This can cause your blood pressure to be too low. For people with heart problems: This includes serious left ventricle dysfunction and heart failure.
Avoid taking verapamil if you have serious damage to the left side of your heart or moderate to severe heart failure. Also, avoid taking it if you have any degree of heart failure and are receiving a beta blocker drug. Verapamil may decrease your blood pressure too much, which may lead to dizziness.
For people with heart rhythm disturbances: These include sick sinus syndrome, ventricular arrhythmias, Wolff-Parkinson-White syndrome, 2 nd or 3 rd degree atrioventricular AV block, or Lown-Ganong-Levine syndrome.
If you have any of these conditions, verapamil may cause ventricular fibrillation or atrioventricular block.
For people with kidney or liver disease: Liver and kidney disease may affect how well your body processes and clears this drug. Having reduced kidney or liver function may cause the drug to build up, which can increase side effects. Your dose may need to be adjusted. For pregnant women: Verapamil is a category C pregnancy drug. That means two things:. Using verapamil during pregnancy may cause negative effects in the fetus such as low heart rate, low blood pressure, and abnormal heart rhythm.
Verapamil should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. For women who are breastfeeding: Verapamil passes through breast milk. It may cause negative effects in a breastfeeding baby. Talk with your doctor before breastfeeding while taking this medication.
This dosage information is for verapamil oral capsules and oral tablets. Dosage The dose of verapamil depends on why you're taking it.
Dosage for high blood pressure Standard tablets or liquid — you'll usually start on a dose of mg, taken twice a day. Liquid verapamil contains 40mg in each 5ml spoonful. Dosage for angina Standard tablets or liquid — the usual dose is 80mg or mg, taken 3 times a day, although some people may find that taking verapamil twice a day is enough to control their symptoms. Dosage for irregular heart rhythm Standard tablets or liquid — the usual dose is between 40mg and mg, taken 3 times a day.
Dosage after a heart attack Slow-release tablets — the usual dose is mg a day, split into 2 or 3 doses throughout the day. Will my dose go up or down? How to take verapamil Swallow your tablets whole with a drink of water. You can take verapamil with or without food. What if I forget to take it? What if I take too much?
Urgent advice: Contact for advice if:. Side effects often get better as your body gets used to the medicine. Common side effects Common side effects happen in more than 1 in people. Talk to your doctor or pharmacist if these side effects bother you or do not go away: constipation feeling or being sick nausea or vomiting flushing of the face and neck headaches feeling dizzy or tired swollen hands, ankles or feet Serious side effects Serious side effects are rare and happen in less than 1 in 10, people.
Stop taking verapamil and tell your doctor straight away if: the whites of your eyes or your skin turn yellow, although this may be less obvious on brown or black skin, or you have dark pee — these can be signs of liver problems Serious allergic reaction In rare cases, it's possible to have a serious allergic reaction anaphylaxis to verapamil.
Information: You can report any suspected side effect using the Yellow Card safety scheme. Visit Yellow Card for further information. What to do about: constipation — eat more high-fibre foods such as fresh fruit, vegetables and cereals, and drink plenty of water.
If you can, it may also help to increase your level of exercise. If this does not help, talk to your pharmacist or doctor about treatments for constipation. It might help to take your verapamil after a meal or snack. If you are being sick, try to take small, frequent sips of water to avoid dehydration.
It might help to keep the room cool and use a fan. You could also spray your face with cool water or sip cold or iced drinks. The flushing should go away after a few days. If it does not go away or it's causing you problems, contact your doctor.
Do not drink too much alcohol. Paracetamol is safe to take with verapamil. Headaches should usually go away after the first week of taking verapamil. Talk to your doctor if they last longer than a week or are severe. If it makes you feel tired make sure you rest and drink plenty of fluids. Do not drive, ride a bike or operate tools or machinery until you feel OK.
This will get better after a few days as your body gets used to the medicine. If it does not, or it gets worse, speak to your doctor. Verapamil and pregnancy Verapamil can be taken during pregnancy, although it is not commonly used.
Verapamil and breastfeeding If your doctor, health visitor or midwife says your baby is healthy, it is OK to breastfeed while taking verapamil. Non-urgent advice: Tell your doctor if you're:. Some medicines can affect the way verapamil works. Tell your doctor if you are taking any of these medicines before starting verapamil: antibiotics, such as clarithromycin , erythromycin or rifampicin antifungal medicines, such as itraconazole or ketoconazole ivabradine, a medicine for angina and heart failure darunavir or ritonavir, medicines that treat HIV or hepatitis C epilepsy medicines like carbamazepine or phenytoin medicines that suppress your immune system, such as cyclosporin or tacrolimus more than 20mg a day of simvastatin a medicine used to lower cholesterol Mixing verapamil with herbal remedies and supplements St John's wort a herbal remedy for depression can affect the way verapamil works.
Talk to a pharmacist or doctor before taking St John's wort. Important: Medicine safety Tell your doctor or pharmacist if you're taking any other medicines, including herbal medicines, vitamins or supplements.
How does verapamil work? Verapamil is a type of medicine called a calcium channel blocker. How long does it take to work? How long will I take it for? Can I stop taking verapamil? Talk to your doctor if you want to stop taking verapamil. Are there other medicines for high blood pressure? There are several other calcium channel blockers that can be used for high blood pressure such as: amlodipine diltiazem felodipine nifedipine There are also lots of other types of medicines to lower your blood pressure.
They work in a different way to calcium channel blockers and include: ACE inhibitors such as ramipril and lisinopril angiotensin receptor blockers such as candesartan beta blockers like bisoprolol diuretics such as bendroflumethiazide The medicine your doctor prescribes depends on your age and ethnicity. Are there other medicines for angina?
There are other calcium channel blockers that can help with angina symptoms, such as: amlodipine diltiazem nifedipine There are also other medicines used to prevent angina attacks. They include: beta blockers such as bisoprolol nitrates such as isosorbide mononitrate medicines such as ranolazine, nicorandil or ivabradine These medicines work in different ways so it's difficult to say whether one is better than the other.
Are there other medicines for an irregular heart rhythm? Some other medicines which are used for arrhythmias and help control heart rate include: beta blockers such as bisoprolol or atenolol digoxin flecainide amiodarone These medicines all work differently and side effects can vary.
Can I take verapamil with painkillers? Will it affect my contraception? Verapamil will not affect your contraception. Will it affect my fertility? This dosage information is for verapamil oral capsules and oral tablets. All possible dosages and forms may not be included here. Your dose, form, and how often you take it will depend on:. If you have a neuromuscular condition, such as Duchenne muscular dystrophy or myasthenia gravis , your doctor may decrease your dose of verapamil.
However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. Always speak with your doctor or pharmacist about dosages that are right for you. Verapamil oral capsule is used for long-term treatment.
This may lead to hospitalization and death. If you take too much: You may experience dangerously low blood pressure, slowed heart rate, or slowed digestion. You may need to stay for at least 48 hours in a hospital for observation and care. What to do if you miss a dose: If you miss a dose, take it as soon as you can. Never try to catch up by taking two doses at once. This could result in toxic side effects.
How to tell if the drug is working: You may experience dangerously low blood pressure, slowed heart rate, or slowed digestion. A prescription for this medication is refillable. You should not need a new prescription for this medication to be refilled.
Your doctor will write the number of refills authorized on your prescription. To see how well this medication is working, your doctor will monitor your heart activity and blood pressure. They may use an electrocardiogram ECG to monitor your heart activity. Your doctor may instruct you on how to monitor your heart rate and blood pressure at home with an appropriate monitoring device. Your doctor may also periodically test your liver function with a blood test.
There are other drugs available to treat your condition. Some may be more suitable for you than others. Talk with your doctor about possible alternatives. Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional.
You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects.
The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
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