are used to relief pain
From the GREEK an-(without) and algos(pain)
occurs either by blocking pain signals going to the
brain or by interfering with the brain's interpretation
of the signals, without producing anesthesia or loss of
Basically has TWO kinds: NON-NARCOTICS and
Acute pain of a headache – considered mild
Severe pain of dental surgery or trauma – more
potent narcotic analgesics (codeine and
Excruciating chronic pain of arthritis and cancer –
frequent administration of the potent narcotics is
So SEVERE!!!(like cancer) - morphine
Paracetamol (Alaxan, Biogesic, Calpol)
Ibuprofen (Alaxan, Restolax,
Mefanamic Acid (Ponstan, Ponser, Ritemed)
Tramadol (Dolcet, Dolmal, Gesidol, Newdorphin)
Morphine (Morin, Relimal CR)
Anesthetics or Anesthesia are also used to relieve
pain by interfering with the nerve transmission
Derived from the GREEK words an-(without) and
Allows the patient to undergo surgeries and other
procedures without the distress and pain of what
they would experience
Anesthesia – coined by Oliver Wendell Holmes Sr.,
Anesthesia is a pharmacologically induced
reversible state of amnesia, analgesia, loss of
consciousness, loss of skeletal muscle reflexes
and decreased stress response.
General anesthesia: "Drug-induced loss of
consciousness during which patients are not
arousable, even by painful stimulation.“
Patients undergoing general anesthesia can often
neither maintain their own airway nor breathe on
While usually administered with inhalational
agents, general anesthesia can be achieved with
intravenous agents, such as propofol
Inhalational anaesthetic substances are either
volatile liquids or gases and are usually delivered
using an anaesthesia machine.
An anaesthesia machine allows composing a
mixture of oxygen, anaesthetics and ambient air,
delivering it to the patient and monitoring
patient and machine parameters.
Liquid anaesthetics are vaporized in the machine.
Many compounds have been used for inhalation
anaesthesia, but only a few are still in widespread
use. Desflurane, isoflurane and sevoflurane are
the most widely used volatile anaesthetics today.
They are often combined with nitrous oxide.
Older, less popular, volatile anesthetics, include
halothane, enflurane, and methoxyflurane.
Researchers are also actively exploring the use of
xenon as an anaesthetic.
Injection anaesthetics are used for induction and
maintenance of a state of unconsciousness.
Anaesthetists prefer to use intravenous injections
as they are faster, generally less painful and more
reliable than intramuscular or subcutaneous
Among the most widely used drugs are:
Barbiturates such as methohexital and
Benzodiazepines such as midazolam and
Ketamine is used in the UK as "field anaesthesia",
for instance at a road traffic incident, and is more
frequently used in the operative setting in the US.
Nitrous oxide (common adjuvant gas)
Xenon (rarely used)
Thiopental (Previously known as Thiopentone in
thiopental and methohexital - are ultra-short-
acting, and are used to induce and maintain
anesthesia. However, though they produce
unconsciousness, they provide no analgesia (pain
relief) and must be used with other agents
Benzodiazepines - can be used for sedation before
or after surgery and can be used to induce and
maintain general anesthesia.
When benzodiazepines are used to induce general
anesthesia, midazolam is preferred.
Benzodiazepines are also used for sedation
during procedures that do not require general
Like barbiturates, benzodiazepines have no pain-
Propofol is one of the most commonly used
intravenous drugs employed to induce and
maintain general anesthesia.
It can also be used for sedation during procedures
or in the ICU.
Like the other agents mentioned above, it renders
patients unconscious without producing pain
Because of its favourable physiological effects,
"etomidate has been primarily used in sick
Ketamine is infrequently used in anesthesia
practice because of the unpleasant experiences
which sometimes occur upon emergence from
anesthesia, which include "vivid dreaming,
extracorporeal experiences, and illusions.“
However, like etomidate it is frequently used in
emergency settings and with sick patients
because it produces fewer adverse physiological
Unlike the intravenous anesthetic drugs
previously mentioned, ketamine produces
profound pain relief, even in doses lower than
those which induce general anesthesia.
Also unlike the other anesthetic agents in this
section, patients who receive ketamine alone
appear to be in a cataleptic state, unlike other
states of anesthesia that resemble normal sleep.
Ketamine-anesthetized patients have profound
analgesia but keep their eyes open and maintain
While opioids can produce unconsciousness, they
do so unreliably and with significant side effects
The following opioids have short onset and
duration of action and are frequently used during
Sufentanil (Not available in the UK)
The following agents have longer onset and duration
of action and are frequently used for post-operative
Diamorphine, (diacetyl morphine, also known as
heroin, not available in U.S.)
Meperidine, also called pethidine in the UK, New
Zealand, Australia and other countries
Oxycodone, (not available
intravenously in U.S.)
are agents which prevent transmission of nerve
impulses without causing unconsciousness. They
act by binding to fast sodium channels from
within (in an open state). Local anesthetics can be
either ester or amide based.
blidocaine (also known as
ESTER BASED prilocaine
may lead to loss of heart function and death
agitation, confusion, dizziness, blurred vision,
tinnitus, a metallic taste in the mouth, and
nausea that can quickly progress to seizures and