Protracted Administration of Methylphenidate(Ritalin)

Clinical and Laboratory Survey of Fifty Patients

FRANK J. Am, JR., M.D.

• MethylphenidateO is a psychostimulantdrug which differs in several respects from

the other members of this category of phar­maceuticals. Unlike the amphetamines, itdoes not have pressor effects nor does it pro­duce the tachvcardia of caffeine. In the nineyears since this compound became available ithas been employed throughout the world for avariety of clinical indications ranging fromdepressed states to overcoming lethargy. Al­though review of the reports that have ac­cumulated reveal a divergence of opinion con­cerning its antidepressant efficacy and utilityin treating chronic apathetic psychiatric pa­tients, there is substantial agreement thatmethylphenidate is quite valuable for antag­onizing the sedative effects of the neurolepticdrugs.' The compound has been used so ex­tensivelv to counteract drug-induced lethargy,fatigue: or sedation that this has become oneof the principal indications for prescribingmethylphenidate.

'''hen a new drug becomes available it isalmost impossible to know immediately allits potential side effects and hazards. Timeand the administration of the medicine tomany persons with their many idiosyncrasiesare ll('cessary before its true safety can be as­sessed.

Although it is difficult to determine ac­curately how many patients have takenmethylphenidate in the past nine years, a con­servative estimate is five to six million, ofwhom several thousands have taken it con­tinuously for a minimum of one year. Thussufficiently large numbers of individuals haveheen treated with methylphenidate for periods

°The mdhylphenidate hydrochloride (Ritalin) waskindly supplied through thc auspices of the MedicalService Division of CIBA Pharmaceutical Company,Summit, N. J.

leBO

long enough to reasonably assume that itsnoxious effects should have heen observed andto permit an evaluation of its safety.

CLlI"ICAL MATERIAL

The objective of this report is to present ananalysis of the clinical and laboratory findingsin fifty psychiatric patients who have takenmethylphenidate conjointly with a phenothia­zine tranquilizer ( mainly, chlorpromazineand perphenazine) for a period ranging from29 to 54 months. They were randomly select­ed from a large number of patients on com­hined long-term phenothiazine-methylpheni­date therapy. This group consisted of 33women and 17 men (24 to 50 years of age).Diagnostically, they represented a variety ofchronic psychoses (chiefly schizophrenia) andneuroses.

Methylphenidate was administered to thesepatients solely to overcome the lethargy,fatigue, or sedation resulting from whicheverphenothiazine was heing taken for the symp­tomatic control of the basic psychiatric illness.

The initial dosage was individualized ac­cording to the apparent severity of the pheno­thiazine-induced psychomotor retardation.The effective starting dosage ranged from alow of 20 mg. daily to a high of 80 mg. a day.Thereafter dosage was adjusted depending onindividual requirements. Dosage varied, tosome degree, with the total dosage of thephenothiazine the person was receiving. Cen­erally, if the total daily dosage of the pheno­thiazine was reduced, the dosage of methyl­phenidate was also adjusted downward.

Since all the patients in this series were onmaintenance phenothiazine therapy and thedosage of the phenothiazine had been fairlyconstant, the maintenance dosage of methyl-

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phenidate also remained fairly steady. Inthese patients, dosage varied from 20 mg. to60 mg. a day given in divided doses of 10 mg.to 20 mg. two or three times a day. At thetime of this survey, the minimum total dosagetaken was 28,500 mg., and the maximum was114,525 mg. Thus there were sufficientamounts of methylphenidate consumed byevery patient to demonstrate the possibilityof deleterious side effects.

LABORATORY INVESTIGATION

Prior to, and at the termination of this sur­vey each patient had a urinalysis, hematologicstudies (white blood cell and differentialcount) and liver function studies (cephalinflocculation and alkaline phosphatase). Pre­treatment and survey urinalyses were all with­in the normal variation.

The results of hematological studies aregiven in Table I. These were analyzed forany significant changes that might have oc­curred. 1\'0 significant differences were noted.

Table II presents the liver function studies.Only the cephalin flocculation test showedchanges in six patients. Since the alkalinephosphatase test results were normal in thesepeople, the significance of the changes incephalin flocculation is unknown. Whetherthey were due to the phenothiazine, themethylphenidate, the combination of bothdrugs or to other conditions must remainspeculative, although it is our personal beliefthat these changes were not due specificallyto methylphenidate.

CLIKICAL OBSERVATIONS

Numerous clinical and laboratory studieshave shown that methylphenidate is a rela­tively weak sympathomimetic drug with lesstendency to cause overstimulation, suppressappetite, or cause insomnia than the ampheta­mines or other analeptic agents. As a rule, itdoes not produce psychological effects con­ducive to habituation or addiction, althoughthere have been reports of isolated cases ofabuse. Likewise there has been a paucity ofreports of serious side effects or toxic reac­tions.~

In this group of patients, there was not asingle instance of over-stimulation resultingfrom methylphenidate. This may be due tothe fact that each person was simultaneously

May-June, 1964

taking a phenothiazine which may have pre­vented any excessive stimulation. On theother hand, adequate doses of this psycho­stimulant produced the sought-for therapeuticobjective, namely, the counteraction of unde­sirable phenothiazine-caused psychomotor re­tardation. At no time throughout the monthsand years of its continuous administration didmethylphenidate lose its effectiveness in thisrespect. The drug, therefore, was not discon­tinued in these individuals because prior clin­ical experience revealed a resurgence of tran­quilizer-induced lethargy or sedation on dis­continuance. The available evidence indicatesthat tolerance is unlikely with long-term ad­ministration of this drug.

It is well known that chlorpromazine oftencauses a polyphagia at initiation of therapy.Methylphenidate never blocked this effect ofchlorpromazine. Patients on long-term pheno­thiazine treatment thus often gain consider­able weight which was not prevented bymethylphenidate irrespective of the dosagetaken. Results of a comparison between agroup of phenothiazine treated individualswho had not taken methylphenidate with thegroup that did revealed no significant differ­ence in the amount of weight gained by mem­bers of either group.

As a part of the routine surveillance of allpatients under treatment, a record of theirsleep patterns had been kept. A study ofthese records disclosed that methylphenidatehad no perceptible effect on sleep. Some pa­tients often took the medicine very late in theday (occasionally at bedtime) but this did notinterfere with or delay sleep in our study.This, too, may be attributable to the blockingeffect of the phenothiazine, since methyl­phenidate has been reported as causing vary­ing degrees of insomnia and disturbed sleep,especially in hypersensitive individuals iftaken late in the day. Not all the patients inthis survey had dreams resulting from thephenothiazine medication, but those who didreported that methylphenidate did not in­crease or eradicate them.

Because methylphenidate is a psychostim­ulant each person treated with the compoundwas carefully observed for signs or symptomsof habituation or addiction. Despite thelengthy duration of drug administration (upto 54 months), the condition was not observed

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PSYCHOSO~IATICS

TABLE I. RESULTS OF HEMATOLOGICAL STUDIES-RITALIN

PATIENT TIHE WBC POLYS. LYMPHS. HafOS. EOS. BASO.

Pre-Treatment 6700 64 33 2 154 month. 7200 67 29 2 2

2 Pre-Treatment 9100 60 37 253 month. 8600 63 34 2

3 Pre-Treatment 7200 65 30 3 253 month. 8100 59 35 4 2

4 Pre-Treatment 5700 61 37 1 152 month. 8400 60 34 4 2

5 Pre-Treatment 5400 60 35 3 152 month. 6400 58 37 3 2

6 Pre-Treatment 7600 65 33 250 month. 8100 60 33 3 3

7 Pre-Treatment 7300 59 38 2 150 month. 5600 57 39 2 2

8 Pre-Treatment 6600 69 28 250 month. 5200 62 35 2

9 Pre-Treatment 7600 60 36 3 150 month. 6100 60 28 2 2

10 Pre-Treatment 8600 56 39 2 2 149 month. 9800 59 37 3 1

11 Pre-Treatment 6300 64 34 149 month. 8200 63 34 2

12 Pre-Treatment 7000 61 32 5 249 _tho 8300 69 26 3 2

• 13 Pre-Tr••tIDlInt 8350 58 37 3 249 _th. 5600 61 33 4 2

14 Pre·Treatment 7400 64 34 249 month. 6400 60 35 3 2

15 Pre-Treatment 9150 56 40 3 148 _th. 9200 60 37 2 1

16 Pre-Treatment 5450 60 35 4 148 _th. 6150 52 46 2

17 Pra-Treatment 8800 60 35 3 248 _th. 7300 50 48 1 1

18 Pre-Treatment 10,000 57 37 4 248 _th. 5600 60 36 2 2

19 Pre-Treatment 7200 61 37 2 247 _tho 6300 56 39 3 2

20 Pre-Treatment 7400 61 36 2 146 _tho 7100 6Z 35 2 1

21 Pre-Treatment 5300 60 36 3 146 _tb. 8500 58 40 2

22 Pre-Treatment 9100 60 38 245 _tho 6100 58 38 2 2

23 Pre-Treatment 6400 59 37 3 144 _th. 9650 61 36 2 1

24 Pre-Treatment 5800 63 34 2 144 _th. 7600 64 32 2 2

25 Pre-Treatment 9400 58 38 3 143 _tho 9200 61 37 1 1

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TABLE I. RESULTS OF HEMATOLOGICAL STUDIES-RITALIN (continued)

PATIENT TDlE WBC POLYS. LYHPRS. HC8OS. lOS. WO.

26 Pre-Treetment 9900 63 3S 1 142 _the 6700 58 38 3 1

27 Pre-TreetlNnt 9000 64 34 242 _the 6700 56 40 3 1

28 Pre-Treetment 7600 sa 38 2 242 _the 9500 66 28 4 2

29 Pre-Treatment 8300 62 36 241 _the 7000 63 J4 2

30 Pre-Treatment 7500 56 37 5 240 _the 9700 64 32 2 1

31 Pre-Treatment 9200 60 36 340 _th. S400 64 32 3

32 Pre-Treat.-nt 7750 70 2940 _the 7759 61 37

33 Pre-Treatment 5100 62 34 340 month. 6100 60 36 4

34 Pre-Treatment 9500 64 J4 138 month. 8000 62 35 2

35 Pre-Treatment 5900 64 32 338 _tha 6300 59 37 3

36 Pre-Treatment 7450 67 32 137 _the 5600 62 36 1

37 Pre-Treatment 7700 70 27 337 _the 7400 60 36 4

38 Pre-Treatment 5900 64 34 137 _the SOOO 60 37 2

39 Pre-Treatment 7600 65 30 436 _the 9100 64 33 2

40 Pre-Treatment 8350 58 40 236 _the SOOO 60 35 3 2

41 Pre-Treatment 8350 58 40 1 134 montha 5800 73 24 2 1

42 Pre-Treatment 5900 59 35~ 3

34 montha 9500 64 34

43 Pre-Treatment 5600 60 32 6 231 _tha 7600 63 33 3 1

44 Pre-Treatment 9500 62 J4 331 _the 7200 S8 40 2

45 Pre-Treatment 6350 64 J4 0 231 _the 8100 66 27 4 3

46 Pre-Treetment 6500 63 34 231 _the 8000 S8 38 3

47 Pre-Treatment S200 62 J4 2 230 _th. 9000 60 37 3 1

48 Pre-Treatment 9700 66 31 2 130 month. S&OO S6 40 3 1

49 Pre-Treetment 6600 58 40 230 month. 9100 60 38 2

50 Pre-Treetment 7150 60 36 329 _th. 7600 63 J4 3

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PSYCHOSO~IATICS

TABLE II. LIVER FUJI;crlON STUDIES-RITALIN

PATIElIT TIMB C!l'll. noc. ALlALIJIIl PlI08PIlA'WlI

Pr.-Tree_nt 0-0 1.354 _the 0-0 3.2

2 Pre-Tre._nt 0-0 1.553 _the 0-0 1.8

3 Pre-Tre.tment 0-0 1.453 _the 0-0 3.0

4 Pre-Tre._nt 0-0 1.852 monthe 0-0 3.0

5 Pre-Tre.tment 0-0 1.852 _the 0-0 2.2

6 Pre-Tre._nt 0-0 1.450 monthe 0-0 4.0

7 Pre-Treetment 8-0 2.050 _the 0-0 1.5

8 Pre-Tre.tant 0-0 1.050 _nthe O-H 1.7

9 Pre-Tre.tment 0-0 1.550 _the 0-0 4.0

10 Pre-Tre.tant 0-0 1.449 _the 0-0 2.0

11 Pre-Treetment 0-0 3.049 .mthe 0-0 2.0

12 Pre-Tre._nt 0-0 1.549 _the 0-0 2.0

13 Pre-Tre.tment 0-0 2.049 _the 0-0 2.5

14 Pre-Tre._nt 0-0 1.449 _the 0-0 1.5

15 Pre-Tre._nt J.+-:H- 1.048 _the 1+-1+ 2.0

16 Pre-Tre._nt 0-0 2.548 _the 0-0 2.4

17 Pre-Tre._nt 0-0 3.048 _the 0-0 1.5

18 Pre-Tre._nt 0-0 3.048 monthe 0-0 2.0

19 Pre-Tre.tmaot 0-0 1.547 monthe 0-0 2.0

20 Pre-Tre.tment 0-0 2.546 _the 1+-1+ 1.4

21 Pre-Tre._nt 0-0 1.546 _the 0-0 1.0

22 Pre-Tr••tment 0-0 1.845 _the 0-0 2.6

23 Pre-Tre._nt 0-0 2.444 monthe 0-0 2.0

24 Pr.-Tr••tment 0-0 1.644 _the 0-0 1.5

25 Pr.-Tre.tmaot 0-1+ 1.043 _the 1+-:H- 1.9

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TABLE II. LIVER FUl'crION STUDIES-RITALIN (continued)

PATDMT TDl! CEPa. FLOC. ALlCALDU PHOSPHATASE

Z6 Pre-Trea_t 0-0 1.242.mtha 0-0 1.8

27 Pra-Trea_t 0-0 3.442.mtha 0-0 1.8

28 Pre-Trea_t 0-0 1.742 _the 0-0 2.9

29 Pre-Trea_t 0-1+ 1.441 IIlOIltha 1+-2+ 1.6

30 Pre-Treatment 0-0 3.240 IIlOIltha 0-0 2.0

31 Pre-Tr.at.-nt 0-0 1.840 IIlOIltha 0-0 2.0

32 Pre-Treatment 0-0 1.640 IIlOIltba 0-0 1.2

33 Pre-Treat.-nt 0-0 2.240 IIlOIltbe 0-0 3.0

34 Pre-Treat.-nt 0-0 5.238 IIlOIltbe 0-0 3.5

35 Pre-Treatment 0-0 1.638 IIlOIIthe 0-0 1.5

36 Pre-Treatment 0-0 1.637 _the 0-0 1.8

37 Pre-Treat.-nt 0-0 2.237 IIlOIlthe 0-1+ 1.5

38 Pre-Treat.-nt 0-0 1.537 IIlOIlthe 0-0 2.0

39 Pre-Traat.-nt 0-0 3.036 IIIOIltbe 0-0 2.0

40 Pre-Treatment 0-0 4.036 IIlOIltha 0-0 1.6

41 Pre-Traat.-nt 0-0 2.534 IIlOIltha 0-0 1.7

42 Pre-Treatment 0-0 3.034 IIlOIltha 0-0 1.4

43 Pre-Treatment 0-0 1.831 IIlOIlthe 0-0 1.7

44 Pre-Treatment 0-0 3.131 IIlOIlthe 0-0 3.0

45 Pre-Treat.-nt 0-0 1.031 lIlOrIthe 0-0 1.4

46 Pre-Treatment 0-0 1.531 lIlOrIthe 0-0 1.6

47 Pre-Treatment 0-0 2.530 lIlOrIthe 0-0 1.7

48 Pre-Treatment 0-0 1.430 IllOI\the 0-0 2.0

49 Pre-Treatment 0-0 1.829 lIlOrIthe 0-0 1.0

50 Pre-Treatment 0-0 2.029 IIlOIlthe 0-0 1.8

May-June, 1964 185

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PSYCHOSOMATICS

in this group of patients. On the contrary, inevery case, the dosage of methylphenidatewas reduced commensurate with the patient'srequirement for this medicine. In a muchlarger number of patients given this com­pound for varying periods of time, abruptwithdrawal produced no ill effects while inother cases even gradual withdrawal did notproduce any desire for retaking the drug.Thus it can be stated unequivocally thatthough there may be abuses of methylpheni­date, the risk of abuse is definitely minimal.

One of the hazards of psychostimulants andof certain antidepressants, notably the mono­amine oxidase inhibitors, is the exacerbationof delusions, hallucinations, agitation andanxiety, and the production of toxic physicalsymptoms, especially cardiovascular, or a toxicpsychoses. These conditions have occurred inpsychiatric patients treated with these drugseither alone or in combination with the neuro­leptics.3

None of the patients in this study registeredany adverse physical or psychological effectswhich could be attributed to methylphenidate.On the contrary, these patients were on pro­tracted phenothiazine-methylphenidate thera­py because it was beneficial. Improvement intheir underlying ailment was, of course, dueprimarily to the phenothiazine. However,achievement of the positive effect of methyl­phenidate under these circumstances was therelief obtained from the tranquilizer's seda­tion or psychomotor retardation. This, in tum,had the additional advantage of producing anincreased sense of well-being in these in­dividuals without causing any unwanted orundesirable psychological effects.

Since these patients were being treated withseveral drugs simultaneously, a record waskept of their side effects and compared with agroup receiving the same compounds withoutmethylphenidate. The comparison revealedno signi6cant difference in the number or typeof side effects in either group. Thus it ap­pears that methylphenidate does not influencethe occurrence of side effects nor does itblock the usual somatic and toxic effects ofthe phenothiazines.

CO),IMEXT

In psychiatry, as well as in almost all thedisciplines, there is rarely any unanimity of

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opmlOn among doctors about therapeuticmethods or efficacy. No doubt there are thosetherapists who might question the value ofor the need for protracted methylphenidateadministration in overcoming sedation in­duced by tranquilizers. However, there iscompelling evidence that this drug does havea marked ability to antagonize the sedative ef­fects of phenothiazines and other tranquilizers.Because of this, it is often prescribed whenphenothiazine treatment is initiated or whenlarge doses are given. Thereafter, methyl­phenidate is withdrawn. There is, however,a fairly large segment of psychiatric patientson maintenance neuroleptic therapy whosechronic dosage of tranquilizer is such as tocause some lethargy and fatigue. Althoughsome patients are unconcerned about drug­induced lethargy, there are others who areuncomfortably conscious of this phenothiazineeffect. Such patients become anxious aboutthis effect for it interferes with measuring upto their self-imposed standards of day-to-dayliving. In out-patients particularly, this canand does hamper further rehabilitation, sincethey become disinclined to expend energy orinitiative activity. In either group of individ­uals, rational and total care requires that thepsychomotor retardation be abolished or les­sened. Since this cannot be achieved by re­duction of tranquilizer dosage without risk ofresurgence of former symptoms, the alterna­tive is to prescribe a psychostimulant. Clinicalexperience shows that methylphenidate can beutilized in this fashion and that it can be ad­ministered for protracted periods with littlerisk to the patient's physical or psychologicalwell-being.

SUMMARY

To ascertain the safety and utility of long­term methylphenidate administration, 50 pa­tients who had received this drug in combina­tion with maintenance phenothiazine treat­ment were surveyed. These individuals re­ceived from 28,550 mg. to 114,525 mg. ofmethylphenidate over a period of 29 to 54months. A comparison of their pretreatmentand survey urinalyses, white cell count anddifferential, cephalin flocculation and alkalinephosphatase tests did not reveal any signifi­cant changes. Clinically, methylphenidate ef­fectively counteracted phenothiazine-induced

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PROTRACTED ADMINISTRATION OF METHYLPHENIDATE-AYD

sedation without interfering with the bene­ficial effects of the neuroleptic and withoutaggravating the patient's basic psychiatric ail­ment. The dmg did not prevent the usualsomatic and allergic effects of the phenothia­zines. It did not overstimulate, suppress ap­petite nor disrupt sleep. In addition, no evi­dence of tolerance or habituation was noted,nor did the dmg cause any serious side effects.

It also obviates one of the undesirable psy­chological complications of phenothiazinetreatment, namely, anxiety caused by patient'sawareness of tranquilizer oversedation. It isconcluded that long-term methylphenidatetherapy is advantageous in that it expeditesrehabilitation by countering such neuroleptic­caused symptoms as oversedation which can

impede rehabilitation progress, especially innon-hospitalized patients. Moreover, methyl­phenidate can be prescribed for prolongedperiods for those patients who need it with­out the risk of harmful effects on the kidneys,liver, or bone marrow.

REFERENCES

I. Kalinowsky, L. B. and Hoch, P. H.: SomaticTreatments in Psychiatry. New York: Grune &Stratton, 1961.

2. American Medical Association: New and Non­Official Drugs, 1963.

3. Ayd, F. J., Jr.: The current status of major anti­depressants. Amer. Psychiat. Assn. Dist. BranchesPub., 1:213 (Feb.) 1960.

6231 York RoadBaltimore 12, Maryland

-The Functional Pathology of Disease (The Physiologi­cal Basis of Clinical l\ledicine ). Second Edition,Edited by ARTHUR GROLLMAN, M.D., Blakiston Di­vision, McGraw-Hili Book Co., New York.

Although definite syndromes associated with hypothalamic disorders are recognized, littleattention has been given to the functional disturbances of a less striking degree which areattributable to malfunction of this part of the midbrain. . . . In turn, psychic and emotionaldisturbances may, by their effects on hypothalamic function, induce many of the observedautonomic and metabolic disturbances seen in chronic illness or dismissed as "functional" or"psychosomatic" complaints.

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