Q-Phentop (Phentermine + Topiramate)

General information

PHENTERMINE + TOPIRAMATE sold under the brand name Q-Phentop, is a combination of phentermine and topiramate used to treat obesity. Q-Phentop (Phentermine + Topiramate) is used together with dietary changes and exercise. If less than 3% weight loss is seen after 3 months it is recommended the medication be stopped. Phentermine is a stimulant and appetite suppressant and stimulant. Topiramate is an anticonvulsant that has weight loss side effects. PHENTERMINE + TOPIRAMATE was approved for medical use in the United States in 2012.

General Dosing and Administration

Determine the patient's BMI. BMI is calculated by dividing weight (in kilograms) by height (in meters) squared.

In adults with an initial BMI of 30 kg/m2 or greater or 27 kg/m2 or greater when accompanied by weight-related co-morbidities such as hypertension, type 2 diabetes mellitus, or dyslipidemia prescribe Q-Phentop (Phentermine + Topiramate) as follows:

• Take Q-Phentop (Phentermine + Topiramate) once daily in the morning with or without food. Avoid dosing with Q-Phentop (Phentermine + Topiramate) in the evening due to the possibility of insomnia.
• Start treatment with Q-Phentop (Phentermine + Topiramate) 3.75 mg/23 mg (phentermine 3.75 mg + topiramate 23 mg extended-release) daily for 14 days; after 14 days increase to the recommended dose of Q-Phentop (Phentermine + Topiramate) 7.5 mg/46 mg (phentermine 7.5 mg/topiramate 46 mg extended-release) once daily.
• Evaluate weight loss after 12 weeks of treatment with Q-Phentop (Phentermine + Topiramate) .
• If a patient has not lost at least 3% of baseline body weight on Q-Phentop (Phentermine + Topiramate) 7.5 mg/46 mg, discontinue Q-Phentop (Phentermine + Topiramate) or escalate the dose, as it is unlikely that the patient will achieve and sustain clinically meaningful weight loss at the Q-Phentop (Phentermine + Topiramate) 7.5 mg/46 mg dose.
• To escalate the dose: Increase to Q-Phentop (Phentermine + Topiramate) 11.25 mg/69 mg (phentermine 11.25 mg + topiramate 69 mg extended release) daily for 14 days; followed by dosing Q-Phentop (Phentermine + Topiramate) 15 mg/92 mg (phentermine 15 mg/topiramate 92 mg extended-release) once daily.
• Evaluate weight loss following dose escalation to Q-Phentop (Phentermine + Topiramate) 15 mg/92 mg after an additional 12 weeks of treatment.
• If a patient has not lost at least 5% of baseline body weight on Q-Phentop (Phentermine + Topiramate) 15 mg/92 mg, discontinue Q-Phentop (Phentermine + Topiramate) as directed, as it is unlikely that the patient will achieve and sustain clinically meaningful weight loss with continued treatment.
• Q-Phentop (Phentermine + Topiramate) 3.75 mg/23 mg and Q-Phentop (Phentermine + Topiramate) 11.25 mg/69 mg are for titration purposes only.

Q-Phentop Possible side effect

Commonly reported side effects of PHENTERMINE + TOPIRAMATE include: constipation, insomnia, nasopharyngitis, paresthesia, mood disorder, sleep disorder, and xerostomia. Other side effects include: urinary tract infection, anxiety, blurred vision, depression, dizziness, fatigue, influenza, nausea, increased serum creatinine, and dysgeusia. See below for a comprehensive list of adverse effects.
Along with its needed effects, PHENTERMINE + TOPIRAMATE may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking PHENTERMINE + TOPIRAMATE:

Less Common

• Chest discomfort;
• convulsions;
• decreased urine;
• fast, irregular, pounding, or racing heartbeat or pulse;
• loss of appetite;
• mood changes;
• muscle pain or cramps;
• nausea or vomiting;
• numbness or tingling in the hands, feet, or lips;
• shortness of breath;
• unusual tiredness or weakness;

Rare

• Blood in the urine;

• pain in the groin or genitals;

• sharp back pain just below the ribs;    

Some side effects of PHENTERMINE + TOPIRAMATE may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Drug Interactions

View interaction reports for Q-Phentop (Phentermine + Topiramate) and the medicines listed below:

• Adderall (amphetamine / dextroamphetamine);
• Aleve (naproxen);
• Belviq (lorcaserin);
• Benadryl (diphenhydramine);
• bupropion (Wellbutrin, Wellbutrin XL, Wellbutrin SR, Zyban, Buproban, Aplenzin, Budeprion, Forfivo XL, Budeprion XL, Budeprion SR);
• clonazepam (Klonopin, Klonopin Wafer);
• Cymbalta (duloxetine);
• Effexor (venlafaxine);
• fluoxetine (Prozac, Sarafem, Prozac Weekly, Selfemra, Rapiflux);
• gabapentin (Neurontin, Gralise, Gabarone, Fanatrex);
• hydrochlorothiazide (HydroDIURIL, Microzide, Oretic, Esidrix, Ezide, Diaqua, Aquazide H, Hydro Par, Carozide, Loqua);
• ibuprofen (Advil, Motrin, IBU, Advil Liqui-Gels, Children's Motrin, Proprinal, Motrin IB, Childrens Ibuprofen Berry, Advil Children's, Ibuprofen PMR, Ibu-8, Rufen, IBU-200, Motrin Childrens, Advil Migraine, Caldolor, Ibu-Tab, Menadol, Midol Maximum Strength Cramp Formula, Motrin Migraine Pain, PediaCare Children's IB Ibuprofen Pain Reliever/Fever Reducer, Ibu-6, Motrin Pediatric, Genpril, Haltran, Midol IB, Saleto-200, Q-Profen, Saleto-400, Saleto-600, Saleto-800, A-G Profen, Nuprin, Advil Junior;
• levothyroxine (Synthroid, Levoxyl, Tirosint, Levothroid, Levothyrox, Eltroxin, Euthyrox, Unithroid, Oroxine, Eutroxsig, Levo-T, L Thyroxine Roche, Novothyrox, Levotabs, Tirosint-Sol, Levotec, Evotrox);
• Lexapro (escitalopram);
• lisinopril (Zestril, Prinivil, Qbrelis);
• losartan (Cozaar);
• meloxicam (Mobic, Vivlodex, Qmiiz ODT);
• metformin (Glucophage, Glumetza, Glucophage, Fortamet, Riomet);
• Mucinex (guaifenesin)
• omeprazole (Prilosec, Prilosec OTC, Zegerid, Omesec);
• Paxil (paroxetine);
• Prozac (fluoxetine);
• Synthroid (levothyroxine);
• tramadol;
• trazodone (Desyrel, Oleptro, Desyrel Dividose);
• Vitamin B12 (cyanocobalamin);
• Vitamin D3 (cholecalciferol);
• Wellbutrin (bupropion);
• wine;
• Xanax (alprazolam);
• Zoloft (sertraline);

PHENTERMINE + TOPIRAMATE Pregnancy and Breastfeeding Warnings

Use during pregnancy is contraindicated as this drug can cause fetal harm.
Females of reproductive potential should be advised to avoid pregnancy through abstinence or by using effective contraception during therapy.
A negative pregnancy test should be obtained before treatment initiation and monthly thereafter in females of reproductive potential.

Data from pregnancy registries and epidemiology studies indicate an up to 5-fold increased risk of oral clefts (cleft lip with or without cleft palate) with first trimester exposure to topiramate. Animal studies with clinically relevant doses of topiramate revealed embryofetal toxicity, including craniofacial defects; increased mortality; reductions in body weight and skeletal ossification; delayed physical development; and malformations in limbs, ribs, and vertebrae. Evidence of maternal toxicity, such as decreased body weight gain and mortality, were also observed in animal studies with topiramate. Animal reproduction studies have not been conducted with phentermine.

Combination phentermine and topiramate treatment in animals at doses approximately 5 to 6 times the maximum recommended human dose caused offspring toxicity and significantly lower maternal body weight gain. Offspring effects included lower survival after birth; increased limb and tail malformations; reduced body weight; and delayed growth, development, and sexual maturation without affecting learning, memory, fertility, and reproduction.

This drug can cause metabolic acidosis. Metabolic acidosis in pregnancy can result in decreased fetal growth, decreased fetal oxygenation, fetal death, and may affect the ability of the fetus to tolerate labor. If this drug is used during pregnancy or if a patient becomes pregnant while taking this drug, treatment should be discontinued immediately and the patient should be apprised of the potential hazard to a fetus.

A decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother. This drug may be present in human milk because topiramate and amphetamines are excreted in human milk. Phentermine has pharmacologic activity and a chemical structure similar to amphetamines.

Storage

Store Q-Phentop (Phentermine + Topiramate) at room temperature between 68-77 degrees F (20-25 degrees C) away from light and moisture. Do not store the drugs in the bathroom. Keep all drugs away from reach of children and pets.