In 2009 and 2010, hydrocodone was the second most frequently encountered opioid pharmaceutical in drug evidence submitted to U.S. federal, state, and local forensic laboratories as reported by DEAs National Forensic Laboratory Information System (NFLIS) and System to Retrieve Information from Drug Evidence (STRIDE). Pregnancy and breastfeeding
Pregnancy category C: Risk in pregnancy cannot be ruled out. Animal controlled studies have not been conducted with this medication.Low concentrations of paracetamol is excreted through breast milk, however, hydrocodones excretion is unknown. Kidney and liver impairment
Use with caution due to possible risk of toxicity. Side effects
Most common
Lightheadedness
Dizziness
Euphoria
Sedation
Nausea and vomiting
Headaches

Less common
Central nervous system: drowsiness, confusion, lethargy, anxiety, fear, unease, dependence, mood changes, impairment of mental and physical performance
Gastrointestinal system: constipation
Genitourinary system: inability to urinate, bladder spasms
Respiratory depression: decreased rate and effort of breathing
Hearing impairment, permanent hearing loss
Dermatological: rash, itching

Black box warning
"Paracetamol has been associated with cases of acute liver failure, at times resulting in liver transplant or death. Most of the cases of liver injury are associated with the use of paracetamol at doses that exceed 4000 milligrams per day, and often involve more than one paracetamol-containing product." Allergy warning
"Do not take hydrocodone bitartrate and paracetamol tablets if you are allergic to any of its ingredients. If you develop signs of allergy such as a rash or difficulty breathing stop taking hydrocodone bitartrate and paracetamol tablets and contact your healthcare provider immediately."
Further tests showed that Monica struggled with recognizing highly familiar melodies, but that she had no problems in recognizing the voices of well-known speakers. Thus, it was concluded that Monicas deficit seemed limited to music. A later study showed that not only do amusics experience difficulty in discriminating variations in pitch, but they also exhibit deficits in perceiving patterns in pitch.This finding led to another test that was designed to assess the presence of a deficiency in pitch perception. In this test, Monica heard a sequence of five piano tones of constant pitch followed by a comparison sequence of five piano tones in which the fourth tone could be the same pitch as the other notes in the sequence or a completely different pitch altogether. Monica was asked to respond "yes" if she detected a pitch change on the fourth tone or respond "no" if she could not detect a pitch change. Results showed that Monica could barely detect a pitch change as large as two semitones (whole tone), or half steps. While this pitch-processing deficit is extremely severe, it does not seem to include speech intonation. This is because pitch variations in speech are very coarse compared with those used in music. In conclusion, Monicas learning disability arose from a basic problem in pitch discrimination, which is viewed as the origin of congenital amusia. Research
Over the past decade, much has been discovered about amusia. However, there remains a great deal more to learn.