Night Nurse (Acetaminophen,Dextromethorphan,Promethazine)

Uses

Acetaminophen is an analgesic drug used alone or in combination with opioids for pain management, and as an antipyretic agent.

In general, acetaminophen is used for the treatment of mild to moderate pain and reduction of fever. It is available over the counter in various forms, the most common being oral forms.

Acetaminophen injection is indicated for the management of mild to moderate pain, the management of moderate to severe pain with adjunctive opioid analgesics, and the reduction of fever.

Because of its low risk of causing allergic reactions, this drug can be administered in patients who are intolerant to salicylates and those with allergic tendencies, including bronchial asthmatics. Specific dosing guidelines should be followed when administering acetaminophen to children.

Promethazine Theoclate Tablets are an anti-emetic (anti-sickness drug) which helps to prevent, and treat nausea and vomiting, including travel sickness, and vertigo. Promethazine Theoclate contains promethazine which belongs to a group of medicines called phenothiazines. Your doctor may prescribe this medicine for giddiness or light-headedness (vertigo), or for sickness after an operation, and in such cases the tablets should be taken as instructed by your doctor.

Night Nurse (Acetaminophen,Dextromethorphan,Promethazine) is also used to associated treatment for these conditions: Acute Gouty Arthritis, Acute Musculoskeletal Pain, Allergies, Ankylosing Spondylitis (AS), Arthritis, Chills, Cold, Cold Symptoms, Common Cold, Common Cold/Flu, Cough, Cough caused by Common Cold, Coughing caused by Flu caused by Influenza, Dyskinesia of the Biliary Tract, Dyskinesia of the Urinary Tract, Febrile Convulsions, Febrile Illness Acute, Fever, Fibromyalgia Syndrome, Flu caused by Influenza, Headache, Joint dislocations, Menstrual Distress (Dysmenorrhea), Mild pain, Muscle Inflammation, Muscle Injuries, Muscle Spasms, Musculoskeletal Pain, Nasal Congestion, Neuralgia, Osteoarthritis (OA), Pain, Pollen Allergy, Postoperative pain, Premenstrual cramps, Rheumatoid Arthritis, Rhinopharyngitis, Rhinorrhoea, Severe Pain, Sinusitis, Soreness, Muscle, Spasms, Spastic Pain of the Gastrointestinal Tract, Sprains, Tension Headache, Toothache, Upper Respiratory Tract Infection, Whiplash Syndrome, Acute Torticollis, Mild to moderate pain, Minor aches and pains, Minor pain, Moderate Pain, Airway secretion clearance therapy, Antispasmodic, BronchodilationAllergic urticaria, Anaphylaxis, Cough, Dermographism, Motion Sickness, Nasal Congestion, Postoperative pain, Seasonal Allergic Conjunctivitis, Seasonal Allergic Rhinitis, Vasomotor Rhinitis, Acute Allergic Reactions, Dry cough, Perioperative nausea and vomiting, Upper respiratory symptoms, Sedative therapy, Adjunct to anesthesia and analgesia

How Night Nurse (Acetaminophen,Dextromethorphan,Promethazine) works

According to its FDA labeling, acetaminophen's exact mechanism of action has not been fully established - despite this, it is often categorized alongside NSAIDs (nonsteroidal anti-inflammatory drugs) due to its ability to inhibit the cyclooxygenase (COX) pathways. It is thought to exert central actions which ultimately lead to the alleviation of pain symptoms.

One theory is that acetaminophen increases the pain threshold by inhibiting two isoforms of cyclooxygenase, COX-1 and COX-2, which are involved in prostaglandin (PG) synthesis. Prostaglandins are responsible for eliciting pain sensations. Acetaminophen does not inhibit cyclooxygenase in peripheral tissues and, therefore, has no peripheral anti-inflammatory effects. Though acetylsalicylic acid (aspirin) is an irreversible inhibitor of COX and directly blocks the active site of this enzyme, studies have shown that acetaminophen (paracetamol) blocks COX indirectly. Studies also suggest that acetaminophen selectively blocks a variant type of the COX enzyme that is unique from the known variants COX-1 and COX-2. This enzyme has been referred to as COX-3. The antipyretic actions of acetaminophen are likely attributed to direct action on heat-regulating centers in the brain, resulting in peripheral vasodilation, sweating, and loss of body heat. The exact mechanism of action of this drug is not fully understood at this time, but future research may contribute to deeper knowledge.

Promethazine is a an antagonist of histamine H1, post-synaptic mesolimbic dopamine, alpha adrenergic, muscarinic, and NMDA receptors. The antihistamine action is used to treat allergic reactions. Antagonism of muscarinic and NMDA receptors contribute to its use as a sleep aid, as well as for anxiety and tension. Antagonism of histamine H1, muscarinic, and dopamine receptors in the medullary vomiting center make promethazine useful in the treatment of nausea and vomiting.

Dosage

Night Nurse (Acetaminophen,Dextromethorphan,Promethazine) dosage

To prevent travel sickness on short journeys: Promethazine Theoclate should be taken at least one or two hours before travelling. Adults and children aged over 10 yearsshould take one tablet. Children aged 5 to 10 years should be given half a tablet.

To prevent travel sickness onlong journeys: Promethazine Theoclate should be taken at bedtime each night during the journey, startingthe night before you travel.Adults and childrenaged over 10 yearsshould take one tablet.Children aged 5 to 10 years should be given half a tablet.

To treat travel sickness:Adults and children over 10 years should take one tablet as soon as you feel sick, followed by a second tablet the same evening. Take a third tablet the following evening if necessary. Children aged 5 to 10 years should treated in the same way, but with half a tablet each time.

For sickness and vomiting due to other causes, and for treating vertigo: Adults and children aged over 10 years should take one tablet up to three times aday. Children aged 5 to 10 years should be given half a tablet up to three times a day.Alternativelyyou should follow the instructions given by your doctor.

Side Effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with promethazine. Just because a side effect is stated here does not mean that all people using Promethazine Theoclate will experience that or any side effect.

• Drowsiness or feeling tired.
• Dizziness.
• Restlessness.
• Headache.
• Nightmares.
• Blurred vision.
• Difficulty passing urine.
• Dry mouth.
• Confusion.
• Feeling disorientated.
• Unexpected increase in excitability in children.
• Increased sensitivity of the skin to sunlight (photosensitivity). If affected you should avoid sun lamps and direct sunlight while you are taking this medicine.
• Loss of appetite.
• Awareness of your heartbeat (palpitations).
• Abnormal heartbeats (arrhythmias).
• Low blood pressure (hypotension).
• Abnormal movements of the hands, legs, face, neck and tongue, eg tremor, twitching, rigidity (extrapyramidal effects).
• Blood disorders.

Toxicity

LD50 = 338 mg/kg (oral, mouse); LD50 = 1944 mg/kg (oral, rat)

Overdose and liver toxicity

Acetaminophen overdose may be manifested by renal tubular necrosis, hypoglycemic coma, and thrombocytopenia. Sometimes, liver necrosis can occur as well as liver failure. Death and the requirement of a liver transplant may also occur. Metabolism by the CYP2E1 pathway releases a toxic acetaminophen metabolite known as N-acetyl-p-benzoquinoneimine(NAPQI). The toxic effects caused by this drug are attributed to NAPQI, not acetaminophen alone.

Carcinogenesis

Long-term studies in mice and rats have been completed by the National Toxicology Program to study the carcinogenic risk of acetaminophen. In 2-year feeding studies, F344/N rats and B6C3F1 mice consumed a diet containing acetaminophen up to 6,000 ppm. Female rats showed evidence of carcinogenic activity demonstrated by a higher incidence of mononuclear cell leukemia at doses 0.8 times the maximum human daily dose (MHDD). No evidence of carcinogenesis in male rats (0.7 times) or mice (1.2 to 1.4 times the MHDD) was noted. The clinical relevance of this finding in humans is unknown.

Mutagenesis

Acetaminophen was not found to be mutagenic in the bacterial reverse mutation assay (Ames test). Despite this finding, acetaminophen tested positive in the in vitro mouse lymphoma assay as well as the in vitro chromosomal aberration assay using human lymphocytes. In published studies, acetaminophen has been reported to be clastogenic (disrupting chromosomes) when given a high dose of 1,500 mg/kg/day to the rat model (3.6 times the MHDD). No clastogenicity was observed at a dose of 750 mg/kg/day (1.8 times the MHDD), indicating that this drug has a threshold before it may cause mutagenesis. The clinical relevance of this finding in humans is unknown.

Impairment of Fertility

In studies conducted by the National Toxicology Program, fertility assessments have been performed in Swiss mice in a continuous breeding study. No effects on fertility were seen.

Use in pregnancy and nursing

The FDA label for acetaminophen considers it a pregnancy category C drug, meaning this drug has demonstrated adverse effects in animal studies. No human clinical studies in pregnancy have been done to this date for intravenous acetaminophen. Use acetaminophen only when necessary during pregnancy. Epidemiological data on oral acetaminophen use in pregnant women demonstrate no increase in the risk of major congenital malformations. While prospective clinical studies examining the results of nursing with acetaminophen use have not been conducted, acetaminophen is found secreted in human milk at low concentrations after oral administration. Data from more than 15 nursing mothers taking acetaminophen was obtained, and the calculated daily dose of acetaminophen that reaches the infant is about 1 to 2% of the maternal dose. Caution should be observed when acetaminophen is taken by a nursing woman.

The intraperitoneal LD₅₀ in rats is 170mg/kg and in mice is 160mg/kg. The subcutaneous LD₅₀ in rats is 400mg/kg and in mice is 240mg/kg. The oral LD₅₀ in mice is 255mg/kg.

Patients experiencing an overdose of promethazine may present with mild central nervous system and cardiovascular depression, hypotension, respiratory depression, unconciousness, hyperreflexia, hypertonia, ataxia, athetosis, extensor-plantar reflexes, convulsions, dry mouth, flushing, gastrointestinal symptoms, and fixed, dilated pupils. Treat overdoses with symptomatic and supportive treatment, which may include activated charcoal, sodium sulfate, magnesium sulfate, controlled ventilation, diazepam, intravenous fluids, vasopressors, norepinephrine, phenylephrine, anticholinergic antiparkinsonian agents, diphenhydramine, barbiturates, or oxygen.

Precaution

Promethazine Theoclate tablets can make some people feel drowsy, dizzy, confused or disorientated and this may reduce your ability to drive or operate machinery safely. Do not drive or operate machinery until you know how this medicine affects you and you are sure it won't affect your performance. If your child is affected in this way they should avoid potentially hazardous activities such as riding bikes. You should not leave your child unattended after giving them this medicine.

Avoid drinking alcohol while taking Promethazine Theoclate because this is likely to make the above effects more likely or worse.

Promethazine Theoclate tablets may make your skin more sensitive to sunlight than usual, so you should avoid exposing your skin to direct sunlight or sunlamps until you know how your skin reacts. If you can't avoid strong sunlight you should use a sunscreen lotion or make sure your skin is protected with clothing.

This medicine may interfere with some pregnancy tests, causing false negative or false positive results.

If you are due to have any skin prick tests to diagnose allergies you should stop taking Promethazine Theoclate at least 72 hours before the tests. This is because antihistamines can prevent or lessen the skin reactions that indicate an allergy, and so can make the test results unreliable.

Interaction

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start taking Promethazine Theoclate. Similarly, check with your doctor or pharmacist before taking any new medicines while taking Promethazine Theoclate, to make sure that the combination is safe.

Promethazine Theoclate should not be taken by anyone who has taken a type of antidepressant called a monoamine oxidase inhibitor (MAOI), eg phenelzine, tranylcypromine, isocarboxazid, in the previous 14 days.

You are more likely to feel drowsy if you take Promethazine Theoclate with any of the following (which can also cause drowsiness):

• alcohol
• antipsychotic medicines, eg chlorpromazine
• barbiturates, eg phenobarbital
• benzodiazepines, eg diazepam, temazepam
• sedating antihistamines, eg chlorphenamine, brompheniramine, hydroxyzine
• sleeping tablets, eg zopiclone
• strong opioid painkillers, eg morphine, codeine, dihydrocodeine, tramadol
• tricyclic antidepressants, eg amitriptyline.

Volume of Distribution

Volume of distribution is about 0.9L/kg. 10 to 20% of the drug is bound to red blood cells. Acetaminophen appears to be widely distributed throughout most body tissues except in fat.

The volume of distribution of promethazine is approximately 970L or 30L/kg.

Elimination Route

Acetaminophen has 88% oral bioavailability and reaches its highest plasma concentration 90 minutes after ingestion. Peak blood levels of free acetaminophen are not reached until 3 hours after rectal administration of the suppository form of acetaminophen and the peak blood concentration is approximately 50% of the observed concentration after the ingestion of an equivalent oral dose (10-20 mcg/mL).

The percentage of a systemically absorbed rectal dose of acetaminophen is inconsistent, demonstrated by major differences in the bioavailability of acetaminophen after a dose administered rectally. Higher rectal doses or an increased frequency of administration may be used to attain blood concentrations of acetaminophen similar to those attained after oral acetaminophen administration.

A 25mg dose of intramuscular promethazine reaches a C_max of 22ng/mL. Intravenous promethazine reaches a C_max of 10.0ng/mL, with a T_max of 4-10h, and an AUC of 14,466ng*h/mL. Oral promethazine is only 25% bioavailable due to first pass metabolism. Oral promethazine reaches a C_max of 2.4-18.0ng/mL, with a T_max of 1.5-3h, and an AUC of 11,511ng*h/mL.

Half Life

The half-life for adults is 2.5 h after an intravenous dose of 15 mg/kg. After an overdose, the half-life can range from 4 to 8 hours depending on the severity of injury to the liver, as it heavily metabolizes acetaminophen.

The elimination half life of promethazine is approximately 12-15h.

Clearance

Adults: 0.27 L/h/kg following a 15 mg/kg intravenous (IV) dose. Children: 0.34 L/h/kg following a 15 mg/kg intravenous (IV dose).

The intravenous clearance of promethazine is approximately 1.14L/min. The renal clearance of promethazine is 5.9mL/min and the renal clearance of promethazine sulfoxide is 90.4mL/min.

Elimination Route

Acetaminophen metabolites are mainly excreted in the urine. Less than 5% is excreted in the urine as free (unconjugated) acetaminophen and at least 90% of the administered dose is excreted within 24 hours.

An intravenous dose of promethazine is 0.64% eliminated in the urine as the unchanged parent drug, 0.02-2.02% in the urine as desmethylpromethazine, 10% in the urine as promethazine sulfoxide.

Pregnancy & Breastfeeding use

If you are pregnant you should not take Promethazine Theoclate without consulting your doctor first. Promethazine Theoclate should only be used during pregnancy if essential, and only if the expected benefit to the mother outweighs any potential risks to the developing baby. It should not be used during the last two weeks of pregnancy, because if taken during this time it may cause irritability or excitement in the baby after birth. Seek further medical advice from your doctor.

Small amounts of Promethazine Theoclate may pass into breast milk. This is not expected to be harmful to a nursing infant with occasional short-term use of Promethazine Theoclate, but there is a risk that it may cause drowsiness, irritability or excitement in a newborn baby. If you are breastfeeding you should not take Promethazine Theoclate without getting medical advice from your doctor first.

Contraindication

• Children under five years of age.
• People with reduced awareness, slow reactions or extreme drowsiness caused by medicines or illnesses that reduce activity in the central nervous system.
• People who have taken a type of medicine called a monoamine-oxidase inhibitor antidepressant (MAOI) in the past 14 days.
• Children and adolescents who have signs and symptoms suggestive of Reye's syndrome.
• People who are allergic to any ingredients of the tablets.
• Promethazine Theoclate tablets contain lactose and should not be taken by people with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption.

Storage Condition

Store between 15-30° C. Protect from light.

Innovators Monograph

You find simplified version here Night Nurse (Acetaminophen,Dextromethorphan,Promethazine)