Search This Blog

468x60.

728x90

 


Pyruvate is converted to lactate, rather than

glucose, through gluconeogenesis

50% glucose (50 mL) by IV push

CNS, central nervous system; IV, intravenous.

For many alcohol-dependent individuals with significant physical dependence, a

cluster of withdrawal symptoms known as “alcohol withdrawal syndrome” (AWS)

may occur on cessation or reduction of alcohol consumption. Depending directly on

the degree of physical dependence, AWS can range from creating significant

discomfort to mild tremor to alcohol withdrawal-related delirium, hallucinosis,

seizures, and potentially death.

155,156 A gamma-glutamyl transferase (GGT) of 992

units/Lin combination with the patient’s medical history suggests that J.M. is a heavy

drinker. Although J.M.’s AST, ALT, and total bilirubin are elevated, his direct

(unconjugated) bilirubin is within normal limits, suggesting a problem with bilirubin

excretion as would be consistent with viral hepatitis or cirrhosis.

Patients may present with AWS in a variety of settings, because alcohol-dependent

patients may be unrecognized and experience withdrawal after inpatient hospital

admission for unrelated medical reasons. For example, a sample from a primary care

practice indicated that 15% of patients presented with at-risk drinking patterns or

identified alcohol-related problems.

157 Surgical patients should be screened

preoperatively for possible alcohol dependence, to prevent and adequately treat

AWS-related complications during and after surgery.

158

Diagnosis requires cessation or reduction in alcohol use that has been heavy and

prolonged, and two or more of the following symptoms developing within several

hours to a few days after the cessation: autonomic hyperactivity, hand tremor,

insomnia, nausea or vomiting, transient hallucinations or illusions (tactile, visual, or

auditory), psychomotor agitation, anxiety, and generalized tonic–clonic seizures.

1

These symptoms must cause significant distress or impairment of important areas of

functioning, and not be caused by a general medical condition or another mental

disorder. Withdrawal-related seizure is considered a more severe manifestation of

withdrawal, as is alcohol withdrawal delirium (AWD), or delirium tremens as it is

traditionally called. AWD is estimated to have a mortality rate of approximately 5%

of patients who go into alcohol withdrawal.

159 Recognized predictors for AWS

complications include the duration of alcohol consumption, total number of prior

detoxifications from alcohol, and previous withdrawal-related seizures and episodes

of AWD.

160

CASE 90-10, QUESTION 2: How could the severity of J.M.’s withdrawal symptoms be quantitatively

assessed?

Of currently used instruments available for measuring the degree of withdrawal in

an alcohol-dependent patient, the most commonly used is the revised Clinical

Institute Withdrawal Assessment (CIWA-Ar).

161 Additionally the Sedation-Agitation

Scale (SAS) could be used to assess agitation.

162 The CIWA-Ar is a validated tenitem scale used for grading severity of AWS that is often used as an inpatient

assessment of withdrawal. The CIWA-Ar provides a final score with a maximum of

67 points assessing the extent of headache, nausea, tremors, agitation, paresthesia,

sweats, audio and visual disturbances, and lack of awareness of time or location.

Treatment of AWS can be initiated based on a patient’s CIWA-Ar score. A CIWAAr rating of 8 points or less represents mild withdrawal and needs little

pharmacologic support. A rating of 9 to 15 is associated with moderate withdrawal

and may require some pharmacotherapy. A rating more than 15 corresponds to severe

withdrawal, with an increased risk of seizures and AWD. Providers should also

consider concomitant illnesses and medications when interpreting CIWA-Ar scores

because individual items in the scale are not specific to AWS, and likewise some

manifestations of withdrawal may be blunted. The SAS can be used in combination

with the CIWA-Ar to evaluate the level of agitation and consciousness of a patient,

and be linked to administer benzodiazepines on a symptom-triggered regimen when a

patient becomes agitated (for scores >4 on a 7-point scale).

Management of withdrawal

CASE 90-10, QUESTION 3: What drugs are demonstrated to be the most clinically effective for alcohol

withdrawal, particularly in a patient such as J.M. with evidence of cirrhosis?

Benzodiazepines

Benzodiazepines modulate anxiolysis by stimulating GABAA receptors and, in doing

so, substitute pharmacologically for alcohol.

163 They are considered the drugs of

choice for alcohol withdrawal,

158,163,164

long-acting benzodiazepines (e.g.,

chlordiazepoxide and diazepam) and short-acting agents (e.g., lorazepam and

oxazepam) represent the most efficacious pharmacotherapies for the treatment of

acute alcohol withdrawal.

157 They are effective in preventing both first seizures and

subsequent seizures during alcohol withdrawal.

165 Longer-acting benzodiazepines

may provide for easier weaning because they gradually self-taper on metabolism and

excretion; this allows for less fluctuation in plasma drug levels.

166 Longer-acting

benzodiazepines also cause fewer rebound effects and withdrawal seizures on

discontinuation. Shorter-acting agents (e.g., lorazepam or oxazepam), which undergo

phase II hepatic metabolism to inactive metabolites, require more frequent dosing but

may be more appropriate for alcoholics with liver disease and the elderly.

164,167

When used appropriately, all benzodiazepines appear equally effective in

ameliorating the signs and symptoms of alcohol withdrawal; however, the choice of a

benzodiazepine is dependent on factors such as pharmacokinetic properties, dosage

formulation, presence of liver impairment, and ease of dosage titration.

168

(Table 90-

6)

p. 1894

p. 1895

Table 90-6

Suggested Treatment Strategies for Alcohol Withdrawal Syndrome

Protocol Clinical Rationale Drug

Dosing Regimen

(Example) Considerations

FixedSchedule

Regimen

The patient receives a fixed

dose of medication for 2–3

days regardless of the severity

of symptoms. This approach is

generally used in severe alcohol

withdrawal.

Chlordiazepoxide 25 to 100 mg orally

every 2–6 hours or

25 mg IV every 2–4

hours

Protocol fixed dose

and time parameters

are decided

beforehand.

Additional

medication is

provided as needed

when symptoms are

not controlled (e.g.,

the CIWA-Ar score

remains at least 8–

10).

Diazepam 10 mg orally every

1–2 hours

(maximum 60 mg)

or 5–10 mg IV 20–

120 minutes

(maximum 100

mg/hour or 250 mg/8

hour)

Lorazepam On days 1 and 2

give 2–4 mg PO 4

times a day. On

days 3 and 4 give 1–

2 mg PO 4 times a

day. On day 5 give 1

mg PO twice a day.

May use IV or IM

(maximum 20

mg/hour or 50 mg/8

hour).

Symptom-Triggered

Regimen

The patient is assessed every

hour using the CIWA-Ar to

determine the need for

medication. The primary

advantage of this approach is

that less medication is used to

achieve the same control and

less sedation.

Chlordiazepoxide 50–100 mg Less abuse potential

for outpatients, low

cost; long acting 24–

48 hours.

Diazepam 10–20 mg Long duration of

action (20–50

hours), which

provides a smooth

treatment course

with less

breakthrough

symptoms.

Lorazepam 2–4 mg Shorter duration of

action may be more

appropriate for

patients at risk for

prolonged sedation

(e.g., elderly, hepatic

impairment).

Alternative

Therapies

In patients with benzodiazepine

allergy or when use of a

benzodiazepine is deemed

medically inappropriate.

Carbamazepine Taper from 600–800

mg on day 1 down

to 200 mg over 5

days.

400 mg PO TID for

3 days, then 400 mg

PO BID for 1 day,

then 400 mg PO for

1 day

Both carbamazepine

and baclofen are

nonaddicting.

Few drug

interactions.

Cause relatively little

cognitive

impairment.

May be equally efficacious as

benzodiazepines.

Baclofen 5 mg PO TID for 3

days and then

increase to 10 mg

TID

Known to lower the

seizure threshold;

more information is

needed before its

routine use in alcohol

withdrawal.

Adjunctive

Therapies

Adrenergic hyperactivity Clonidine 0.1 mg PO BID as

needed

For mild to moderate

hyperactivity.

Adrenergic hyperactivity β-Blockers:

Atenolol

Metoprolol

50 mg PO daily

2.5–5 mg IV

May improve vital

signs faster than

oxazepam alone.

Up to 3 doses about

2 minutes apart; use

parameters for HR

and blood pressure.

Agitation, hallucinations,

delirium

Neuroleptics:

Haloperidol

Olanzapine

0.5–5 mg PO/IM/IV

every hour; maximal

dose 100 mg/day

10 mg IM

Rapid onset but note

QTc prolongation

(e.g., >450 ms);

recommend baseline

ECG before using

IV.

Maximal dosing,

three 10-mg doses

given 2–4 hours

apart; monitor for

orthostatic

hypotension before

the administration of

repeated doses.

BID, 2 times daily; CIWA-Ar, Clinical Institute WithdrawalAssessment; ECG, electrocardiogram; HR, heart rate;

IM, intramuscular; IV, intravenous; PO, oral; TID, 3 times daily.

Source: Guirguis AB, Kenna GA. Treatment considerations for alcohol withdrawal syndrome. US Pharm.

2005;30:71; Mayo-Smith MF, et al. Management of alcohol withdrawal delirium. An evidence-based guideline

[published correction appears in Arch Intern Med. 2004;164:2068. Dosage error in article text]. Arch Intern Med.

2004;164:1405.

p. 1895

p. 1896

DOSE

Two strategies for dosing benzodiazepines in AWS include fixed-schedule and

symptom-triggered regimens. Fixed-schedule regimens involve a set dose and

interval for the agent chosen, which is to be tapered off at specific times, usually

starting on the second day of treatment. Symptom-triggered regimens depend on the

use of a rating scale of withdrawal severity, such as the CIWA-Ar previously noted,

which is repeated at set intervals. Medication is only administered if the scoring

from the scale is above a predetermined threshold value for treatment. In this way,

the risk of undermedicating or overmedicating patients may be minimized, because

the degree of withdrawal symptoms guides dosing. Several studies confirm that

symptom-triggered regimens compared with fixed-dose regimens appear to result in a

shorter duration of necessary therapy and less medication administered in total

without any loss of efficacy.

168

The treatment challenge associated with individuals who are in alcohol

withdrawal with a comorbid medical illness is illustrated by the case of a patient

with AWS who has coronary artery disease. Such a patient may be more aggressively

treated for withdrawal-related hypertension and thus treated with a β-blocker or

clonidine. The result of such adjuvant treatment may be a reduced sensitivity of the

CIWA-Ar owing to a masking of the patient’s autonomic manifestations of

withdrawal. This could then lead to a higher likelihood of undermedicating the

patient for withdrawal and may put the patient at higher risk for severe sequelae from

withdrawal. Because of these exclusion criteria, the symptom-triggered approach has

not been tested in such populations or those with histories of severe withdrawal

including seizures or delirium. Therefore, traditional fixed-dose regimens are

recommended in these populations.

168 An effective approach is most likely to

consider combining these two dosing strategies. For example, a low-risk patient (no

history of AWS or AWD, the patient consumes low weekly amounts of alcohol and

has no signs or symptoms of early AWS) receives a symptom-triggered regimen (e.g.,

lorazepam 1 mg every hour as needed). Alternatively, a high-risk patient (history of

AWS, AWD, or withdrawal seizures, consumes large daily amounts of alcohol, has

signs or symptoms of early AWS) receives fixed-dose lorazepam or diazepam with a

tapering dose schedule and as needed benzodiazepine administration for uncontrolled

alcohol withdrawal signs or symptoms. Importantly, phenobarbital, dexmedetomidine

and propofol are useful adjuncts to benzodiazepines if an inpatient has severe

symptoms.

168

CONTRAINDICATIONS, WARNINGS, AND INTERACTIONS

Elderly patients, those with hepatic or renal insufficiency, and those with medical

(e.g., diabetes, cirrhosis) or other psychiatric illnesses (e.g., dementia) require close

observation to prevent overmedication. As noted above, patients receiving calciumchannel blockers, β-blockers, and α2

-adrenergic agonists, some signs of withdrawal

such as hypertension, tachycardia, and tremor may not be apparent.

Patients with a history of severe withdrawal symptoms, withdrawal seizures, or

delirium tremens; multiple previous detoxifications; concomitant psychiatric or

medical illness; recent high levels of alcohol consumption; pregnancy; and lack of a

reliable support network should be considered for inpatient treatment regardless of

the severity of their symptoms.

168

Lorazepam is the only benzodiazepine with predictable intramuscular absorption

(if intramuscular administration is necessary). Rarely, it is necessary to use

extremely high dosages of benzodiazepines to control the symptoms of alcohol

withdrawal. Controlled studies comparing the advantages and disadvantages of the

various benzodiazepines in alcohol detoxification have not been performed, and no

evidence exists to definitively support the use of lorazepam as the first-line agent in

the treatment of AWS.

168,169

In most patients with mild to moderate withdrawal symptoms, outpatient

detoxification is safe and effective, and costs less than inpatient treatment. If

outpatient treatment is chosen, the patient and support person(s) should be instructed

on how to take the prescribed medication, its side effects, the expected withdrawal

symptoms, and what to do if symptoms worsen. Small quantities of the withdrawal

medication, especially benzodiazepines, should be prescribed at each visit. Because

close monitoring is not available in outpatient treatment, a fixed-schedule regimen

should be used.

Given J.M.’s elevated liver enzymes, a reasonable approach would be to start

with lorazepam. Shorter-acting agents, such as lorazepam, which do not undergo

extensive hepatic metabolism, are more appropriate for patients with evidence of

hepatic insufficiency.

ADJUNCTIVE TREATMENTS

CASE 90-10, QUESTION 4: What adjunctive therapeutic support might be considered for J.M.?

The hydration, electrolyte (especially potassium and magnesium), and nutritional

status of patients should be assessed at presentation. Support with IV fluids may be

necessary in those patients with excessive losses through vomiting, sweating, and

hyperthermia.

170 Thiamine and multivitamins as well as folate 1mg should be

routinely administered to patients in alcohol withdrawal. If IV fluids are given, to

prevent precipitation of Wernicke encephalopathy thiamine administration should

precede that of glucose.

160 Alcohol-dependent patients are deficient of thiamine and

have a higher risk for developing Wernicke encephalopathy.

171 The condition is a

triad of acute mental confusion, ataxia, and ophthalmoplegia. Korsakoff amnestic

syndrome is a late neuropsychiatric manifestation of Wernicke encephalopathy with

memory loss and confabulation; hence, the condition is referred to as Wernicke–

Korsakoff syndrome. It is most often seen in chronic alcohol use disorder patients,

but it can also be seen in disorders associated with malnutrition, e.g., long-term

hemodialysis or patients with acquired immunodeficiency syndrome (AIDS).

172

Thiamine deficiency results in a decrease in cerebral glucose utilization. The body

usually stores about 3 weeks of thiamine with daily requirements of about 1.5 mg.

Rapid correction of brain thiamine deficiency can occur with high plasma

concentrations of thiamine, achieved by parenteral supplementation only because

absorption of the oral thiamine by the GI tract is minimal (<5%), even with massive

oral daily dosing.

171 Patients should receive at least 200-500mg TID IV for 3 days to

prevent the neuropsychiatric effects of thiamine deficiency.

172

Several adjunctive medications, aside from the sedative-hypnotics, may serve

ancillary roles in the therapy of AWS. Their selection should be based on treating

specific symptoms associated with the syndrome. For instance, β-blockers

(propranolol,

173 atenolol

174

) or α2

-adrenergic agonists (e.g., clonidine

175 or

dexmedetomidine if in an ICU) can be used for moderate to severe hypertension or

other autonomic manifestations. α2

-adrenergic agonists are preferred because it

reduces NE outflow from the nerve and addresses all hyperadrenergic effects instead

of just effecting the β receptors with a β-blocker, and delirium seems to be more

common with the β-blocker use.

168,169 Antipsychotics (e.g., haloperidol, quetiapine)

can be used for managing hallucinations and severe agitation, but care must be used

because these drugs can reduce the seizure threshold.

163,168,176

p. 1896

p. 1897

PHARMACOTHERAPY OF ALCOHOL

DEPENDENCE

CASE 90-11

QUESTION 1: R.M. is a 55-year-old man, weighing 140 lb, who used to drink about 60 drinks a week before

going through alcohol detoxification. R.M. is married and has a good job, and he is now committed to remain

alcohol abstinent. R.M. heard about a drug called disulfiram from a friend and is interested in using this

medication to help him abstain from drinking. Laboratory values obtained today include the following:

Sodium, 132 mEq/L AST, 30 units/L

Potassium, 3.3 mEq/L ALT, 35 units/L

CO2

, 22.6 mEq/mL Uric acid, 9.1 mg/dL

Chloride, 109 mEq/L Calcium, 8.7 mg/dL

BUN, 14 mg/dL Magnesium, 1.7 mg/dL

Creatinine, 1.0 mg/dL Albumin, 4.0 g/dL

Glucose, 123 mg/dL Cholesterol, 255 mg/dL

Total bilirubin, 0.3 mg/dL CK, 78 units/L

Direct bilirubin, 0.1 mg/dL GGT, 30 units/L

ALP, 53 units/L

Is disulfiram an appropriate agent to consider for R.M.?

In order to assess alcohol use disorder treatments an accurate medical history,

including laboratory test results. In addition, several instruments are available to

screen and delineate the extent of a patient’s alcohol use. Ultimately, time and

purpose for use are always major factors when deciding which instrument to use. The

simplest screen to assess risk of alcohol abuse is to ask the patient, during the past

year on how many occasions have you had five or more drinks (for a man) or four or

more drinks (for a woman) at one time?

177 An affirmative answer would suggest that

further follow-up of the patient’s alcohol use history is needed. A second tool called

the C-A-G-E consists of four questions: (1) Have you ever felt you should cut down

on your drinking?; (2) Have people annoyed you by criticizing your drinking?; (3)

Have you ever felt bad or guilty about your drinking?; and (4) Have you ever felt you

needed a drink first thing in the morning to steady your nerves or get rid of a

hangover (eye opener)? Positive responses to two questions suggest an alcohol

problem (Table 90-7).

178 The Alcohol Use Disorders Identification Test (AUDIT),

which was developed by the World Health Organization, has also been shown to be

effective in screening individuals and distinguishing problem drinkers from others.

179

Pharmacotherapy

The pharmacologic treatments of alcohol dependence focus on relapse prevention

once detoxification is complete and the patient has achieved a few days of

abstinence. Treatment is intended to be an adjunct to psychosocial treatments and not

used alone.

180 To date, disulfiram, acamprosate, and naltrexone tablet and injection

have been FDA-approved for the treatment of alcohol dependence. In addition,

several other drugs have shown varying degrees of success such as quetiapine,

ondansetron, and others.

180–202 Yet much is still unknown about the long-term rates of

abstinence, how long these drugs should be used once patients are in treatment, the

optimal doses, and whether the drugs are more effective in men or women or for

which specific subpopulations.

203

DISULFIRAM

Table 90-7

Useful Screens for Assessing Alcohol Problems

The C-A-G-E Screening Questions (CAGE)

Have you ever felt you should cut down on your drinking?

Have other people annoyed you by criticizing your drinking?

Have you ever felt guilty about drinking?

Have you ever taken a drink in the morning to calm your nerves or get rid of a hangover (eye opener)?

Methods for Determining Recent Alcohol Consumption

Acute consumption

Blood alcohol concentration

Urine (ethyl glucuronide)

Saliva

Breath alcohol concentration

Recent heavy consumption

Gamma-glutamyl transferase (GGT)

Carbohydrate-deficient transferrin (CDT)

Mean corpuscular volume (MCV)

Disulfiram is an irreversible acetaldehyde dehydrogenase inhibitor that blocks

alcohol metabolism, leading to an accumulation of acetaldehyde. Disulfiram

reinforces an individual’s desire to stop drinking by providing a disincentive

associated with increased acetaldehyde levels, resulting in headache, palpitations,

hypotension, flushing, nausea, and vomiting when patients consume alcohol. The

primary predictor of success with disulfiram is the patient’s commitment to total

abstinence from alcohol. Although anecdotal reports of success are common, clinical

evidence suggests disulfiram appears to be most effective for alcoholics who are

involved in special high-risk situations (e.g., weddings, graduations) and is

particularly effective when administration is supervised.

3,180

Controlled clinical trials of disulfiram have clearly shown efficacy, yet this has

not been a consistent finding.

180 Double-blind, placebo-controlled studies using

disulfiram are difficult because the psychological deterrent to use alcohol is

experienced by both treatment groups and those who relapse will be unblinded when

they experience the pharmacologic interaction.

In the most rigorous clinical trial conducted in a population of veterans, no

significant difference in abstinence rates was demonstrated between patients taking

placebo or 1 mg or 250 mg of disulfiram.

181 Patients randomly assigned to receive

250 mg of disulfiram daily drank less frequently (significantly fewer drinking days

per year), however. Patients who were middle-aged and had social stability were

more likely to benefit from disulfiram. In another trial in which administration was

supervised, patients receiving disulfiram drank less alcohol and less frequently;

however, on randomization, patients were unblinded to their drug.

204

No comments:

Post a Comment

اكتب تعليق حول الموضوع

mcq general

 

Search This Blog