Orlistat is a medication used for weight management, particularly in the treatment of obesity. It works by inhibiting pancreatic lipase, an enzyme that breaks down triglycerides in the intestine. By blocking this enzyme, Orlistat prevents the absorption of dietary fat in the intestine, leading to reduced calorie intake and subsequent weight loss.

Orlistat is typically prescribed along with a reduced-calorie diet and exercise program. It's not a magic pill for weight loss but rather a tool to aid in the process. The reduction in fat absorption can lead to gastrointestinal side effects such as oily spotting, flatulence, fecal urgency, and fatty or oily stools. These side effects can be managed with dietary adjustments and are usually temporary.

Xenical (Orlistat, Orslim) inhibits gastric and pancreatic lipases resulting in the inhibition of dietary fats absorption.

Orlistat Uses:

It is used as an adjunct to a low-calorie diet and exercise for the management of obesity.

It is available at a lower dose as OTC medicine for weight loss. For the treatment of obesity that may include losing weight and maintaining weight loss, higher doses may be used that require a prescription. It is only indicated for weight loss if the BMI is 30 kg/m² or more or if the BMI is 27 kg/m² or more in the presence of other risk factors like diabetes, hypertension, and dyslipidemia. It is among the five prescription weight loss pills approved by the AACE (American association of clinical endocrinologyy) and ACE (American college of Endocrinologist)

Orlistat (Xenical) Dose in Adults:

Orlistat (Xenical) dose in the treatment of Obesity management: 

• Xenical Dosage: For Xenical, the prescribed dose is 120 mg taken orally three times a day. You take it with each main meal that contains fat, either during the meal or within an hour after eating. If you miss a meal or if the meal doesn't have any fat, you can skip that dose.
• Alli Dosage (Over-the-counter): If you're taking Alli, the recommended dose is 60 mg three times a day with each main meal that contains fat. The maximum dose you can take in a day is 180 mg.

Dosing Adjustment with Other Medications:

• Cyclosporine: If you're taking cyclosporine along with Orlistat, make sure to take cyclosporine three hours after you've taken Orlistat.
• Levothyroxine: If you're also taking levothyroxine, it's important to take it and Orlistat at least four hours apart. Additionally, your doctor should monitor your thyroid function regularly to check for any changes.

These dosing adjustments are important to ensure the effectiveness of each medication and to minimize any potential interactions or side effects.

Orlistat (Xenical) dose in Childrens

Orlistat (Xenical) dose in the treatment of Obese children:

• Children 12 years of age or older: Refer to adult dosing

Pregnancy Risk Factor X

• Using Orlistat during pregnancy is not recommended because there isn't enough information about its effects on pregnant women and their babies.
• Studies show that being overweight during pregnancy can lead to health problems for both the mother and the baby.
• But gaining weight within a healthy range before pregnancy is important for a positive outcome.
• Since Orlistat is used for weight loss, it's not safe to take it when you're pregnant.
• It could harm the baby without providing any real benefit to the mother.
• So, pregnant women should avoid taking Orlistat.

Orlistat use during breastfeeding:

• It's uncertain whether Orlistat passes into breast milk because it's not fully absorbed into the bloodstream.
• The manufacturer suggests being cautious if using Orlistat while breastfeeding.
• Since Orlistat is mostly limited to the digestive system and doesn't get absorbed much into the body, the risk to breastfeeding infants is likely low.

Orlistat (Xenical) dose in Kidney disease:

• The manufacturer's labeling for Orlistat does not include dosage adjustments for individuals with renal impairment because this population hasn't been specifically studied.
• However, it's unlikely that dosage adjustments are necessary because Orlistat is minimally absorbed into the bloodstream.
• Since the medication primarily works in the digestive system and isn't extensively absorbed by the body, it's less likely to be affected by changes in kidney function.

Orlistat (Xenical) Dose in liver disease:

• The manufacturer's labeling for Orlistat doesn't include specific dosage adjustments for individuals with hepatic (liver) impairment because this population hasn't been studied.
• However, it's unlikely that dosage adjustments are necessary because Orlistat is minimally absorbed into the bloodstream.
• Since the medication primarily acts in the digestive system and isn't extensively absorbed by the body, it's less likely to be affected by changes in liver function.

Side effects of Orlistat (Xenical):

• Cardiovascular:
  • Pedal Edema
• Central Nervous System:
  • Headache
  • Fatigue
  • Anxiety
  • Sleep Disorder
• Dermatologic:
  • Xeroderma
• Endocrine & Metabolic:
  • Menstrual Disease
  • Hypoglycemia
• Gastrointestinal:
  • Oily Rectal Leakage
  • Abdominal Distress
  • Abdominal Pain
  • Flatulence With Discharge
  • Bowel Urgency
  • Steatorrhea
  • Oily Evacuation
  • Frequent Bowel Movements
  • Nausea
  • Fecal Incontinence
  • Infectious Diarrhea
  • Rectal Pain
  • Gingival Disease
  • Cholelithiasis
  • Abdominal Distension
• Genitourinary:
  • Urinary Tract Infection
  • Vaginitis
• Infection:
  • Influenza
• Neuromuscular & Skeletal:
  • Back Pain
  • Leg Pain
  • Myalgia
• Otic:
  • Otitis
• Respiratory:
  • Upper Respiratory Tract Infection
  • Lower Respiratory Tract Infection

Contraindications to Xenical (Orlistat):

• If you're allergic to Orlistat or any ingredients in it, pregnant, have a condition where your body has trouble absorbing nutrients properly over a long time (chronic malabsorption syndrome), or if you have cholestasis (a problem with bile flow from the liver), you should not use Orlistat.

Warnings and precautions

Cholelithiasis

• Losing a lot of weight quickly can increase the chances of getting cholelithiasis, which are gallstones in the gallbladder.
• So, if you're using Orlistat or any other method for significant weight loss, there's a possibility that it could raise the risk of developing gallstones.

Hepatotoxicity:

• Orlistat has been associated with severe liver damage, including cases where the liver cells die (hepatocellular necrosis) or acute liver failure, which can be fatal.
• Some patients have needed a liver transplant due to this.
• People taking Orlistat should be aware of symptoms of liver problems, such as loss of appetite, itching, yellowing of the skin or eyes, dark urine, pale stools, or pain in the upper right side of the abdomen.
• If any of these symptoms occur, it's crucial to stop taking Orlistat immediately and get liver function tests done.

Increased urinary oxalate

• Orlistat treatment can lead to higher levels of oxalate in the urine for some people, which may increase the risk of developing kidney stones made of oxalate and even kidney damage.
• There have been cases of kidney stone formation and kidney damage linked to oxalate.
• Therefore, it's important to keep an eye on kidney function in patients who might be at risk for kidney problems.
• Orlistat should be used cautiously in individuals with a history of high oxalate levels or kidney stones made of calcium oxalate.

Diabetes:

• For individuals with diabetes, it's crucial to closely monitor their condition while using Orlistat because weight loss can affect blood sugar control.
• Changes in weight might require adjustments to diabetes medications to maintain proper blood sugar levels.
• Therefore, regular monitoring of blood sugar levels and possibly adjusting the dosage of antidiabetic medications may be necessary while taking Orlistat.
• This ensures that diabetes management remains effective and safe during the weight loss process.

Orlistat: Drug Interaction

Monitor:

• BMI: Keep an eye on your Body Mass Index (BMI) to track changes in weight.
• Weight: Regularly weigh yourself to monitor your progress.
• Diet: Pay attention to your calorie and fat intake as advised by your healthcare provider.
• Serum Glucose (for Diabetes): If you have diabetes, monitor your blood sugar levels closely.
• Liver Function: Be aware of any symptoms of liver problems and get liver function tests if needed.
• Renal Function: If you're at risk for kidney issues, monitor your kidney function regularly.

How to administer Orlistat? How to take Xenical?

• Timing: Take Orlistat during or within one hour after each main meal that contains fat.
• Multivitamins: Wait at least two hours after taking Orlistat before consuming a multivitamin that contains fat-soluble vitamins.
• Skipping Dose: If you miss a meal or if a meal doesn't contain any fat, skip that dose of Orlistat.

Mechanism of action of Orlistat (Xenical MOA):

• Orlistat is a medication that works by temporarily blocking the activity of certain enzymes in the stomach and pancreas, called gastric and pancreatic lipases.
• By doing this, it reduces the absorption of dietary fats by about 30%.
• This means that when you take Orlistat with meals, your body absorbs less fat from the food you eat, which can aid in weight loss.

Onset of Action:

• It typically starts working within 24 to 48 hours after taking the medication.

Duration:

• The effects of Orlistat can last for 48 to 72 hours.

Absorption:

• Orlistat is minimally absorbed into the bloodstream after oral administration.

Protein Binding:

• More than 99% of Orlistat binds to proteins in the blood, particularly lipoproteins and albumin.

Metabolism:

• Orlistat undergoes metabolism within the walls of the gastrointestinal tract, forming inactive metabolites.

Half-life Elimination:

• The half-life of Orlistat in the body is relatively short, ranging from 1 to 2 hours.

Time to Peak Serum Levels:

• Orlistat reaches peak levels in the blood approximately 8 hours after administration.

Excretion:

• Orlistat and its metabolites are primarily eliminated through feces (about 97%, with 83% as unchanged drug) and a small amount through urine (less than 2%).

International Brand Names of Orlistat:

• Alli
• Xenical
• Aslene
• Beacita
• Bodyslend
• Cuvarix
• Digrasil
• Eliza
• Fatlose
• Lakshmi
• Lessfat
• Lipidown
• Lysta
• Nofat
• Obestat
• Odistad
• Oliet
• Orlifit
• Orlis
• Orlist
• Orly
• Ornical
• Orslim
• Prolistat
• Redustat
• Sidelg
• Slimfast
• Verte
• Viplena
• Xenical
• Xenista
• Xenobese
• Zero-X
• Zerodown

Orlistat Brand Names in Pakistan: