Overdose
Hydrocodone: Respiratory depression, extreme somnolence progressing towards coma, muscle limpness, cold and clammy skin, slow heart rate, low blood pressure, abrupt loss of heart function, and death may occur.Paracetamol: Liver and kidney failure, low blood sugar coma may occur. Interactions
Hydrocodone may demonstrate an enhanced respiratory depressant effect when combined with other sedatives such as other opioids, benzodiazepines, nonbenzodiazepine sedatives, psychotropics, and anticonvulsants.Concurrent use of paracetamol with alcohol products may increase the risk of acute liver failure. Monitoring
Laboratory function tests should be used to monitor therapy in people with severe liver or renal disease. Pharmacology
Hydrocodone
Mechanism of action: Hydrocodone acts primarily as an agonist at the mu-opioid receptors, but is also a weak agonist against the delta opioid and kappa opioid receptors. Absorption/distribution: The oral formulation can be absorbed from the gastrointestinal tract and remain 20–50% bound to plasma proteins. The onset of analgesia is about 20 to 30 minutes with duration of 4 to 8 hours and t1/2 of 3 to 4 hours. Metabolism/excretion: It is metabolized to norhydrocodone by cytochrome P450 3A4 and to hydromorphone, also biologically active, by cytochrome P450 2D6. For individuals who have a defect in the gene encoding CYP2D6, the clearance of the drug will be lower and less metabolite such as hydromorphone will be formed; however, the effect on analgesia remains unknown. Paracetamol
Mechanism of action: Paracetamol acts to inhibit COX enzyme, which is responsible for prostaglandin synthesis. Prostaglandins increase the perception of pain. Inhibition of prostaglandin production helps to alleviate pain.
So, the patient uses excessive accommodation to stimulate accommodative convergence to overcome reduced PFV. Risk factors
A large amount of near work is the main precipitating factor of accommodative excess. Pseudomyopia
Pseudomyopia also known as artificial myopia  refers to an intermittent and temporary shift in refractive error of the eye towards myopia. It may occur due to excessive accommodation or spasm of accommodation. Diagnosis
Differential diagnosis
Parinaud’s syndrome, which can mimic some aspects of spasm of the near reflex, such as excessive accommodation and convergence; however, pupillary near-light dissociation, not miosis, is a feature of Parinaud’s syndrome. Treatment
Optical: Cycloplegic refraction, and correction of Refractive errors if any 
Vision therapy
General: Relax from near work

See also
Spasm of accommodation
Convergence excess


== References ==