Aciphex vs Prilosec

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For patients with gastroesophageal reflux disease (GERD) or other types of stomach acid-related conditions, certain drugs that reduce the production of stomach acid can help in relieving symptoms such as heartburn and indigestion. Aciphex and Prilosec are two such drugs commonly prescribed for these conditions. Both medications act by inhibiting an enzyme called proton pump on the cells lining the stomach, which is responsible for producing stomach acid, thereby lowering its levels. Aciphex (rabeprazole) has a slightly faster onset of action compared to Prilosec (omeprazole), starting to take effect within one hour versus two hours respectively; however, both have similar overall efficacy in reducing gastric acidity. They belong to a class of medication known as proton pump inhibitors (PPIs).

What is Aciphex?

Rabeprazole (the generic name for Aciphex) is a newer drug in the class of proton pump inhibitors, which marked a significant development upon the earlier class of antacid medications. Rabeprazole was first approved by the FDA in 1999. Aciphex works by reducing levels of stomach acid, effectively "trapping" it within the stomach's cells to prevent it from causing damage to your esophagus or intestines. It is prescribed primarily for people with gastroesophageal reflux disease (GERD) and other conditions involving excessive stomach acid.

Omeprazole (the generic name for Prilosec) serves similar functions but has been around longer as it was approved by the FDA in 1989. Like Aciphex, Prilosec also reduces gastric acid production but does so through slightly different mechanisms.

Both drugs have very few side effects due to their specific targeting of gastric parietal cells - these are the cells responsible for secreting gastric acid. However, long-term use may result in vitamin B12 deficiency among other potential issues due to reduced absorption caused by lack of stomach acidity.

What conditions is Aciphex approved to treat?

Aciphex and Prilosec are both approved for the treatment of various acid-related stomach conditions:

  • Gastroesophageal reflux disease (GERD)
  • Zollinger-Ellison syndrome, which causes overproduction of stomach acid
  • Erosive esophagitis, a type of inflammation in the esophagus
  • Duodenal ulcers In addition to these, Prilosec is also approved for the treatment of gastric ulcers.

How does Aciphex help with these illnesses?

Aciphex (rabeprazole) manages gastroesophageal reflux disease (GERD) by reducing the amount of acid produced in the stomach. It does this by inhibiting proton pumps, which are enzymes found on gastric parietal cells that contribute to the final step of gastric acid production. Gastric acid plays a vital role in digestion but can cause discomfort and damage when it's overproduced or regurgitates into the esophagus, leading to conditions like GERD or peptic ulcer disease. Therefore, by decreasing gastric acid production, Aciphex helps limit these negative effects and assists patients in managing their condition.

Similarly, Prilosec (omeprazole) also works as a proton pump inhibitor with its mechanism focusing primarily on blocking the enzyme system which secretes gastric acids into the stomach. This action helps treat symptoms associated with excess stomach acidity including heartburn and inflammation of the esophagus among others.

Both medications work similarly but vary slightly in their chemical composition which may result in different interaction patterns with other drugs or varied side effects from person to person.

What is Prilosec?

Prilosec, also known by its generic name omeprazole, is a type of medication called a proton pump inhibitor (PPI). This means it works to reduce the production of stomach acid by blocking the enzyme in your stomach’s wall that produces it. First approved by the FDA in 1989, Prilosec has been widely used for treating conditions such as gastroesophageal reflux disease (GERD), peptic ulcers and Zollinger-Ellison syndrome. Unlike Aciphex which is only available via prescription, Prilosec can be bought over-the-counter or prescribed for more severe cases. Its side effects are different from those of H2 blockers like cimetidine; specifically, it does not typically cause drowsiness and is less likely to interact with other medications. Furthermore, patients who do not respond well to traditional antacids or H2 blockers may find relief with PPIs such as Prilosec.

What conditions is Prilosec approved to treat?

Prilosec is a proton pump inhibitor that has been approved by the FDA for the treatment of several conditions, including:

  • Gastroesophageal reflux disease (GERD)
  • Gastric ulcers
  • Duodenal ulcers
  • Prevention of gastric ulcers caused by nonsteroidal anti-inflammatory drugs (NSAIDs)

It's also used in combination with certain antibiotics to treat Helicobacter pylori infection, which can lead to these types of ulcers.

How does Prilosec help with these illnesses?

Prilosec, much like Aciphex, is a proton pump inhibitor (PPI) that works by decreasing the amount of acid produced in the stomach. Prilosec functions by binding to an enzyme in the lining of the stomach known as H+/K+ ATPase, also known as a gastric proton pump. This inhibits its function and effectively reduces secretion of gastric acid. It's commonly prescribed for the treatment of gastroesophageal reflux disease (GERD), peptic ulcer disease, and other conditions involving excessive stomach acid production. Compared to Aciphex, Prilosec may be preferred due to its availability over-the-counter and lower cost while maintaining similar effectiveness for these conditions. However, it must be noted that individual responses can vary and some patients might respond better or tolerate one drug over another.

How effective are both Aciphex and Prilosec?

Both rabeprazole (Aciphex) and omeprazole (Prilosec) are proven effective in managing gastroesophageal reflux disease (GERD), peptic ulcers, and other conditions related to excessive stomach acid. These proton pump inhibitors were approved by the FDA only a few years apart, with Prilosec getting approval in 1989 and Aciphex in 1999.

A randomized clinical trial conducted in 2002 compared the effectiveness of Aciphex and Prilosec for treating symptomatic GERD; both drugs demonstrated comparable efficacy at relieving heartburn symptoms as well as similar safety profiles. In this study, none of the different metrics used to measure symptom relief differed significantly between patients receiving Aciphex or those taking Prilosec.

A review published in 2005 showed that omeprazole is highly effective from the first week of treatment, has a favorable side effect profile compared to many other acid reducers, and is generally well-tolerated among most populations. The same report indicated that it was one of the most commonly prescribed medications worldwide due to its wide therapeutic applications.

On another hand, a meta-analysis done in 2010 suggested that rabeprazole could be marginally more effective than placebo at treating GERD symptoms, but overall had similar efficacy to other common proton pump inhibitors including omeprazole. While usually considered alongside other treatments rather than immediately being chosen as a first-line option, significant research on its use shows promise when co-prescribed with antibiotics for eradication therapy against H.pylori infections. However data confirming its standalone superiority over omeprazole isn't robust enough yet. Nonetheless owing to certain pharmacokinetic advantages like faster onset of action & lesser drug interactions , rabeprazole may be an optimal choice for some patients such as elderly or those needing rapid symptom relief.

abstract image of a researcher studying a bottle of drug.

At what dose is Aciphex typically prescribed?

Oral dosages of Aciphex range from 20–40 mg/day, but studies have indicated that a daily dose of 20 mg is sufficient for treating gastroesophageal reflux disease (GERD) in most people. Adolescents aged 12 and above may be started on a regimen of 20 mg/day. In either population, the dosage can be increased after several weeks if there is no response. The maximum dosage that should not be exceeded in any case is 40 mg/day.

On the other hand, Prilosec comes in doses ranging from 10 to 40mg per day for adults and adolescents over the age of seventeen with conditions such as heartburn or GERD. The typical starting dose for those new to this medication is often around 20mg per day taken an hour before eating your first meal. If symptoms persist without improvement after four to eight weeks, it's important to consult your healthcare provider who might adjust the dosing schedule accordingly.

At what dose is Prilosec typically prescribed?

Prilosec therapy is typically initiated at a dosage of 20 mg/day taken before eating. An increase to two doses per day, each of 20 mg and spaced approximately 12 hours apart, can be considered if symptoms persist or are severe. The maximum dose is usually not more than 40 mg/day divided into two doses of 20mg given twice daily. This might be tested if there's no response to the initial treatment after a few weeks. Always remember that it's imperative to follow your healthcare provider's guidance on medication usage and adjustments.

What are the most common side effects for Aciphex?

Side effects of Aciphex and Prilosec can vary, but some of the most common include:

  • Headache
  • Diarrhea or constipation
  • Nausea or vomiting
  • Stomach pain (dyspepsia)
  • Dry mouth
  • Dizziness
  • Insomnia (difficulty sleeping) or somnolence (sleepiness/drowsiness)
  • Rash, potentially causing itching or discomfort
  • Back pain
  • Coughing, potentially leading to sinusitis (inflammation of the sinus cavities in the head)
    If you experience any of these symptoms persistently when taking either Aciphex or Prilosec, it is important that you consult with your healthcare provider.

abstract image of a patient experiencing side effect

Are there any potential serious side effects for Aciphex?

When comparing Aciphex to Prilosec, it's important to note that both medications are generally safe but can cause serious side effects in rare cases. These may include:

  • Kidney problems: swelling in your feet or ankles, blood in your urine, or little or no urination.
  • Symptoms of lupus (an autoimmune disorder): joint pain or a rash on the cheeks and arms that worsens with exposure to sunlight.
  • Signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
  • Severe stomach pain, diarrhea that is watery or bloody.
  • Bone fractures if used long-term daily
  • Low magnesium levels - dizziness and irregular heartbeat Severe nausea, vomiting and/or weight loss.

If you experience any of these symptoms while taking either Aciphex (rabeprazole) or Prilosec (omeprazole), immediately consult with your healthcare provider.

What are the most common side effects for Prilosec?

Prilosec, like any other medication, can cause certain side effects. These may include:

  • Headache
  • Nausea, vomiting, stomach pain
  • Diarrhea or constipation
  • Gas (flatulence)
  • Dizziness or lightheadedness
  • Sleep problems such as insomnia or unusual dreams
  • Rash or itchy skin While these side effects are not common and usually mild when they do occur, if you experience severe symptoms such as chest pain, unexplained weight loss, dark urine or signs of an allergic reaction after taking Prilosec, seek immediate medical attention.

Are there any potential serious side effects for Prilosec?

While Prilosec is generally well-tolerated, it may cause severe side effects in rare cases. These could include:

  • Signs of an allergic reaction such as hives, itching, difficulty breathing or swallowing, swelling in your face or throat
  • New or worsening symptoms of lupus: joint pain and a skin rash on your cheeks or arms that worsens when exposed to sunlight.
  • Symptoms related to low magnesium including seizures (convulsions), dizziness and abnormal or fast heart beat
  • Kidney problems: urinating less than usual, blood in your urine, swelling in your feet or ankles
  • Severe diarrhea caused by Clostridium difficile bacteria
  • Unusual changes in mood or behavior

If you experience any of these symptoms while taking Prilosec, seek immediate medical attention.

Contraindications for Aciphex and Prilosec?

Both Aciphex and Prilosec, along with most other proton pump inhibitors (PPIs), may exacerbate symptoms of digestive disorders in some cases. If you notice your symptoms worsening or an increase in abdominal pain, severe nausea, vomiting, unexplained weight loss, blood in stool or vomit, please seek immediate medical attention.

Neither Aciphex nor Prilosec should be taken if you are taking drugs like rilpivirine, atazanavir or nelfinavir which are essentially HIV medication. Always tell your physician about all the medications you are currently taking; Certain medicines require a period to clear from the system to prevent dangerous interactions with Aciphex and Prilosec.

Long-term use of PPIs can lead to low levels of magnesium in your body causing fatigue, involuntary muscle contractions or arrhythmia. It's crucial for patients on either Aciphex or Prilosec for more than a year to have their magnesium levels checked regularly.

It is also important to note that sudden discontinuation after long term use can lead to acid rebound - a condition where stomach produces more acid than normal.

How much do Aciphex and Prilosec cost?

For the brand name versions of these drugs:

  • The price of 30 tablets of Aciphex (20 mg) averages around $230, which works out to about $7.67 per day.
  • The price of 42 capsules of Prilosec OTC (20 mg) is approximately $22, working out to roughly $0.52/day.

Thus, if you are in need for daily acid reflux treatment, then brand-name Prilosec is less expensive on a per-day treatment basis than Aciphex. Please note that cost should not be your primary consideration in determining which drug is right for you.

In terms of generic versions–rabeprazole (Aciphex) and omeprazole (Prilosec):

  • Rabeprazole can range from about $60 for 30 tablets (~$2/day), but prices may vary depending on location and pharmacy.
  • Generic omeprazole costs significantly less than its brand-name counterpart - as low as $5 for an over-the-counter pack of 14 capsules ($0.35/day).

However, bear in mind that although cheaper options exist with generics and over-the-counter versions available, it's important to consult with your healthcare provider before making any changes regarding medications.

Popularity of Aciphex and Prilosec

Rabeprazole, which is sold under the brand name Aciphex among others, was prescribed around 2.5 million times in the US in 2020. It accounts for just over 3% of proton pump inhibitor (PPI) prescriptions in the country. Rabeprazole is classified as a PPI and its use has been relatively consistent over recent years.

Omeprazole, commonly known by the brand name Prilosec, on the other hand, was prescribed to nearly 21 million people in America during the same year. In terms of market share for PPIs within USA, omeprazole holds around 28%. The prevalence of this medication has seen an increase since it became available as an over-the-counter drug about a decade ago.


Both Aciphex (rabeprazole) and Prilosec (omeprazole) have a well-established history of use in managing gastroesophageal reflux disease, peptic ulcer disease, and other conditions associated with excess stomach acid. They are both proton pump inhibitors that work by decreasing the amount of acid produced in the stomach. While they can be used interchangeably in many cases, choice between them may rest on individual patient factors or responses.

Aciphex is often favored for its faster onset of action compared to Prilosec. However, as both drugs inhibit gastric acid secretion for an extended period, this difference might not be clinically significant for most patients.

Both medications are available in generic versions which offer substantial cost savings especially for those who must pay out-of-pocket. Both Aciphex and Prilosec may require some time before their full effects are observed due to the nature of their mechanism.

The side effect profiles are similar between these two drugs; they're generally well-tolerated but may cause minor side effects such as diarrhea, nausea or headaches. There's also potential risk regarding long-term use related to bone fractures and certain infections due to reduced stomach acidity levels. Patients should closely monitor any unusual symptoms when starting treatment with either drug and seek immediate medical attention if severe reactions occur.