Methadone HCL Syringe Side Effects by Likelihood and Severity

COMMON side effects


If experienced, these tend to have a Severe expression

  • Abnormally Low Blood Pressure

If experienced, these tend to have a Less Severe expression

  • Constipation
  • Dizzy
  • Drowsiness
  • Feel Like Throwing Up
  • Feeling Faint
  • Feeling Weak
  • Throwing Up

INFREQUENT side effects


If experienced, these tend to have a Severe expression

  • Confused
  • Decreased Lung Function
  • Fast Heartbeat
  • Slow Heartbeat
  • Trouble Breathing

If experienced, these tend to have a Less Severe expression

  • Blood Pressure Drop Upon Standing
  • Chronic Trouble Sleeping
  • Dry Mouth
  • Excessive Sweating
  • False Sense Of Well-Being
  • Head Pain
  • Kidney Problems Causing A Decreased Amount Of Urine To Be Passed
  • Loss Of Appetite
  • Nervous
  • Problems With Eyesight
  • Spasm Of A Bile Duct Tract
  • Stomach Cramps
  • Ureteral Spasm

RARE side effects


If experienced, these tend to have a Severe expression

  • Abnormal Heart Rhythm
  • Complete Stoppage Of The Heart
  • Decreased Function Of The Adrenal Gland
  • Deficiency Of A Substance That Promotes Masculinization
  • Fluid In The Lungs
  • Hallucination
  • Heart Failure
  • Hives
  • Increased Spinal Fluid Pressure
  • Itching
  • Life Threatening Allergic Reaction
  • Low Amount Of Magnesium In The Blood
  • Low Amount Of Potassium In The Blood
  • Lung Failure Causing Loss Of Breath
  • Prolonged QT Interval On EKG
  • Rash
  • Rhabdomyolysis
  • Seizures
  • Serotonin Syndrome - Adverse Drug Interaction
  • Shock
  • Ventricular Fibrillation
  • Very Rapid Heartbeat - Torsades De Pointes

If experienced, these tend to have a Less Severe expression

  • Absence Of Menstrual Periods
  • Agitation
  • Altered Interest In Having Sexual Intercourse
  • Cannot Empty Bladder
  • Decreased Ability Of Sperm To Swim
  • Deficient Activity Of The Testis
  • Delay When Starting To Pass Urine
  • Heart Throbbing Or Pounding
  • Inability To Have An Erection
  • Inflammation Of A Vein
  • Low Sperm Count
  • Painful, Red Or Swollen Tongue
  • Problems Getting Pregnant
  • Temporary Redness Of Face And Neck
  • Visible Water Retention
  • Weight Gain

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CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.